import type { NativePlanQuestionCall, PlanCountTranscript } from './plan-count-transcript';
import type { AskUserQuestionFingerprint } from './claude-pty-runner';
import { hasRetainedLegacyCorpus } from './eng-retained-corpus';

/** Evidence for this fixture's four decision seeds; regression coverage is auto-added by the skill. */
export const ENG_DECISION_SEEDS = ['complexity', 'shared-cache', 'swallowed-errors', 'sequential-idp'] as const;
type Seed = typeof ENG_DECISION_SEEDS[number];

// Ignore displayed examples/code, while retaining inline code identifiers.
function prose(text: string, omitLiteralProse = false): string {
  let fence: string | undefined;
  const lines = text.split('\n').filter(line => {
    const mark = line.match(/^ {0,3}(`{3,}|~{3,})/);
    if (mark) {
      if (!fence) fence = mark[1];
      else if (mark[1][0] === fence[0] && mark[1].length >= fence.length) fence = undefined;
      return false;
    }
    return !fence && !/^(?: {0,3}>| {4}|\t)/.test(line);
  }).join('\n');
  return (omitLiteralProse ? lines.replace(/`([^`]+)`/g, (span, body: string) => /\s/.test(body) ? '' : span) : lines).replace(/[`*]/g, '');
}

function seedSubjects(q: NativePlanQuestionCall['questions'][number]): Seed[] {
  // The actual issue subject, not cross-references in recommendations or other options,
  // assigns credit. ELI10 can identify what a terse Promise.all title operates on.
  const subject = q.question.split('\n').find(line => line.trim())?.trim() ?? '';
  if (/^(?:>|`{3}|~{3}|example\b|quote\b|["“])|\b(?:no (?:issue|defect)|already (?:fixed|resolved)|hypothetical)\b/i.test(subject)) return [];
  const title = subject.replace(/[`*]/g, '');
  // A concise decision title can name the design choice while its own
  // current explanation states the defect. Keep these three forms bound to
  // that explanation and the same native option's concrete repair.
  const decisionTitle = title.replace(/^D[1-9]\d*\s*[—–:-]\s*/, '');
  const tenantWriters = /^Architecture issue [1-9]\d*: two services write the same tenant-keyed cache with no serialized mutations\. Who owns writes\?$/i.test(decisionTitle);
  const decomposition = /^Reduce the ([2-9]\d*)-component decomposition or proceed as-is\?$/.exec(decisionTitle);
  const rewrittenErrors = /^How should validateAndDispatch\(\) handle errors after the rewrite\?$/.test(decisionTitle);
  const ownedRewriteChoice = Boolean(decomposition || rewrittenErrors);
  if (ownedRewriteChoice && /^`[^`]*`[.?]?$/.test(subject.replace(/^D[1-9]\d*\s*[—–:-]\s*/, ''))) return [];
  const explainedSeed: Seed | undefined = /^Reduce the new-class count before we review the rest\?$/.test(decisionTitle) || decomposition ? 'complexity'
    : /^Who is allowed to write to the auth cache\?$/.test(decisionTitle) || tenantWriters ? 'shared-cache'
    : /^How should validateAndDispatch\(\) handle errors\?$/.test(decisionTitle) || rewrittenErrors ? 'swallowed-errors' : undefined;
  if (explainedSeed) {
    const ordinal = /^D([1-9]\d*)\s*[—–:-]/.exec(title)?.[1];
    const status = '(?:withdrawn|rejected|cancelled|canceled|superseded|resolved|fixed|optional|hypothetical|unproven|not current|no longer current)';
    const owner = `(?:(?:this|the|that) (?:finding|issue|decision|gap|defect|assessment|explanation)${ordinal ? `|D${ordinal}` : ''})`;
    const current = (value: string, option = false) => {
      const subject = option ? `(?:${owner}|(?:this|the|that) (?:option|action|remedy|correction))` : owner;
      const scalar = new RegExp(`((?:^|[.!?;]\\s+|\\n)[\\t ]*(?:Correction:\\s*)?${subject} (?:is|was|has been) )["“'‘\x60](${status})["”'’\x60]`, 'gim');
      const formatted = ownedRewriteChoice ? value.replace(/\*\*/g, '') : value;
      return prose(formatted.replace(scalar, '$1$2'), true).replace(/"[^"\n]*"|“[^”\n]*”|(?<![A-Za-z0-9])'[^'\n]*'(?![A-Za-z0-9])|‘[^’\n]*’/g, '');
    };
    const framed = /(?:^|[.!?;:]\s+|\n)(?:(?:Project\/branch\/task|ELI10):\s*)?(?:Source(?: excerpt| material)?|Quoted(?: source)?|Historical(?: assessment| example)?|If approved|Once approved|When approved|Pending approval|Assuming approval|Provided approval)[,:.]?\s/i;
    const active = (value: string, option = false) => {
      const text = current(value, option), subject = option ? `(?:${owner}|(?:this|the|that) (?:option|action|remedy|correction))` : owner;
      if (ownedRewriteChoice && (/\b(?:if|once|when|unless) (?:approved|accepted)|\b(?:after|pending) approval\b/i.test(text) ||
        /(?:^|[.!?;]\s+|\n)(?:Correction:\s*)?(?:this|the|that) (?:finding|issue|option|action|remedy|correction) (?:applies|proceeds|will proceed) only if\b/i.test(text))) return false;
      return !framed.test(text) && !new RegExp(`(?:^|[.!?;]\\s+|\\n)(?:Correction:\\s*)?${subject} (?:is|was|has been) ${status}\\b`, 'i').test(text) &&
        !(option && /(?:^|[.!?;]\s+|\n)(?:Correction:\s*)?(?:do not|don't|never|skip|cancel|withdraw) (?:drop|reduce|inject|flatten|rethrow|make|apply)\b/i.test(text)) &&
        !(ownedRewriteChoice && option && /(?:^|[.!?;]\s+|\n)(?:Correction:\s*)?(?:do not|don't|never|skip|cancel|withdraw) (?:cut|remove|split|propagate)\b/i.test(text));
    };
    const text = current(q.question), explanations = [...text.matchAll(/^ELI10: (.+)$/gm)];
    // A current correction about the named component/function overrides its
    // earlier defect assertion; quoted history has already been removed.
    if (decomposition && /(?:^|[.!?;]\s+|\n)(?:Correction:\s*)?(?:AuthCache (?:now |already )?has independent policy rules|TokenStore (?:now |already )?has a documented independent purpose)\b/i.test(text) ||
        rewrittenErrors && /(?:^|[.!?;]\s+|\n)(?:Correction:\s*)?validateAndDispatch\(\) (?:now |already )?(?:rethrows every error|no longer swallows failures)\b/i.test(text)) return [];
    const prefix = text.slice(text.indexOf('\n') + 1, explanations[0]?.index ?? 0).trim().split('\n').filter(Boolean);
    if (explanations.length !== 1 || (prefix.length !== 1 && !(tenantWriters && prefix.length === 2 && /^\[P[0-3]\]/.test(prefix[1]!))) ||
        !/^Project\/branch\/task: \S/.test(prefix[0]!) || !active(q.question)) return [];
    const explanation = explanations[0]![1]!;
    const options = q.options.filter(o => active(`${o.label}\n${o.description ?? ''}`, true))
      .map(o => ({ label: current(o.label).replace(/^[1-9]\d*[A-D]\s+/, ''), description: current(o.description ?? '') }));
    // A numbered decomposition choice owns its inventory and redundant-wrapper
    // explanation. Keep the cut and injected-adapter remedy in the same option.
    if (decomposition) {
      const inventory = /, ([A-Za-z][\w]*(?: \+ [A-Za-z][\w]*)+)\.$/.exec(prefix[0]!)?.[1]?.split(' + ') ?? [];
      const pieces = /^The plan builds (five|[1-9]\d*) new pieces, but one working cache already does the storing and invalidating\./.exec(explanation);
      return new Set(inventory).size === Number(decomposition[1]) && inventory.length === Number(decomposition[1]) &&
        ['AuthBroker', 'SessionMint', 'AuthCache', 'TokenStore'].every(name => inventory.includes(name)) &&
        pieces && Number(pieces[1] === 'five' ? 5 : pieces[1]) === Number(decomposition[1]) &&
        /\bAuthCache is described as a facade over that adapter with no new rules, and TokenStore is never described at all\./.test(explanation) &&
        options.some(o => {
          const cut = /^(?:[A-D][):.]\s*)?(?:Cut|Drop|Remove) AuthCache \+ TokenStore, keep ([1-9]\d*)\b/.exec(o.label);
          return cut && Number(cut[1]) === inventory.length - 2 &&
            /^(?:✅\s*)?AuthBroker and SessionMint depend on the existing adapter through one small injected interface; no facade, no second store\./.test(o.description);
        }) ? ['complexity'] : [];
    }
    // The future repair concerns a currently swallowing function, established
    // by its own metadata; a general error-handling question is insufficient.
    if (rewrittenErrors) return /\bvalidateAndDispatch\(\) is [1-9]\d* lines with (?:three|[1-9]\d*) nested try\/catch blocks that each swallow a different error class\b/.test(prefix[0]!) &&
      /^When an auth function catches an error and quietly moves on, the request continues as if the check passed or never mattered\./.test(explanation) &&
      options.some(o => /^(?:[A-D][):.]\s*)?Split into validate\(\) \+ dispatch\(\); one typed error boundary, deny-by-default\b/.test(o.label) &&
        /^(?:✅\s*)?Each error class maps to an explicit AuthOutcome \(denied\/retryable\/misconfigured\) with a reason; nothing is swallowed, unknown errors deny\b/.test(o.description) ||
        /^(?:[A-D][):.]\s*)?Keep one function; flatten the three catches into one that logs and rethrows$/.test(o.label) &&
        /\bErrors are no longer silent; every failure is logged and surfaced\./.test(o.description)) ? ['swallowed-errors'] : [];
    if (tenantWriters) return /\bAuthBroker\b/.test(prefix[0]!) && /\bSessionMint\b/.test(prefix[0]!) &&
      /^Two services writing the same cache entry at the same time is a race\./.test(explanation) &&
      !/(?:^|[.!?]\s+|\n)(?:Correction:\s*)?(?:the|this) (?:cache|writes|writers) (?:is|are|have been) (?:now ordered|now serialized|no longer shared)\b/i.test(text) &&
      options.some(option => {
        const actors = /\b(AuthBroker|SessionMint) is the only service that writes validated entries;\s*(AuthBroker|SessionMint) reads\b/.exec(option.description);
        return /^[1-9]\d*[A-D][):.]\s*Single writer \+ generation check\b/.test(option.label) && actors && actors[1] !== actors[2] &&
          /\bEach write carries the tenant generation read at validation start; the adapter rejects a write whose generation is stale\b/.test(option.description);
      }) ? ['shared-cache'] : [];
    if (explainedSeed === 'complexity') {
      const wrapper = /^The plan invents a new cache wrapper \(([A-Za-z][\w]*)\) and a new token store on top of a cache adapter that already does tenant keying, expiry, and invalidation\./.exec(explanation);
      return wrapper && options.some(o => /^Reduce\b/.test(o.label) &&
        new RegExp(`\\bdrop ${wrapper[1]}\\/TokenStore classes\\.`).test(o.description)) ? [explainedSeed] : [];
    }
    if (explainedSeed === 'shared-cache') return /\bAuthBroker and SessionMint both mutating one backing cache\b/.test(prefix[0]!) &&
      /^Two services write to the same cache and nothing orders their writes\./.test(explanation) &&
      !/(?:^|[.!?]\s+|\n)(?:Correction:\s*)?(?:the|this) (?:cache|writes|writers) (?:is|are|have been) (?:now ordered|now serialized|no longer shared)\b/i.test(text) &&
      options.some(o => /^Single writer\b/.test(o.label) && /^SessionMint writes\b/.test(o.description) && /\bAuthBroker reads\b/.test(o.description)) ? [explainedSeed] : [];
    return /\bvalidateAndDispatch\(\) is [1-9]\d* lines, (?:three|[1-9]\d*) nested try\/catch blocks, each catch swallows a different error class\b/.test(prefix[0]!) &&
      /^Right now when something goes wrong inside validation, the code catches the problem and keeps going as if nothing happened\./.test(explanation) &&
      options.some(o => /^Flatten \+ typed errors\b/.test(o.label) && /\bLinear pipeline, typed error classes, one fail-closed boundary\b/.test(o.description) ||
        /^Rethrow, one outer catch$/.test(o.label) && /\brethrow typed errors; outer catch denies\b/.test(o.description)) ? [explainedSeed] : [];
  }
  const offered = q.options.map(o => `${o.label} ${o.description ?? ''}`).join('\n');
  const directAction = title.match(/\b(?:should|shall|can|do|would)\s+(?:we|I)\s+([^?]+)\?\s*$/i)?.[1];
  const action = (re: RegExp) => re.test(offered) || Boolean(directAction && new RegExp(`^(?:${re.source})`, re.flags).test(directAction));
  // A shared adapter title may name its cache in the issue's own asserted
  // explanation. Options alone or a neighboring source excerpt cannot do so.
  const adapterPublic = prose(q.question, true);
  const adapterExplanations = [...adapterPublic.matchAll(/^ELI10:\s*(.+)$/gm)];
  const adapterPrefix = adapterPublic.slice(0, adapterExplanations[0]?.index ?? 0).split('\n').filter(line => line.trim()).slice(1);
  const adapterMetadata = adapterPrefix.join(' ').replace(/"[^"\n]*"|“[^”\n]*”/g, '');
  const adapterExplanation = adapterExplanations.length === 1 && adapterPrefix.every(line => /^(?:Project\/branch\/task:|\[P[0-3]\])/.test(line))
    && !/\b(?:copied|quoted|source|hypothetical|historical)\s+(?:(?:source|quoted)\s+)?(?:example|excerpt|text|material)\b|\b(?:ELI10|assessment|finding)\s+is\s+not\s+(?:a\s+)?current\b/i.test(adapterMetadata)
    ? adapterExplanations[0]![1]! : '';
  const adapterAssessment = adapterPublic.replace(/"[^"\n]*"|“[^”\n]*”/g, '');
  const sharedAdapter = /\bwrite-after-invalidate race\b/i.test(title)
    && /\bSessionMint\b/.test(title) && /\bAuthBroker\b/.test(title) && /\bshared adapter\b/i.test(title)
    && /^(?:Even after injection,\s*)?(?:both|the two) services (?:write into|mutate) the same cache\./i.test(adapterExplanation)
    && !/\b(?:(?:this|that|the) (?:issue|finding|race)|Issue\s+[1-9]\d*)\s+(?:is|was|has been)\s+(?:withdrawn|retracted|rejected|resolved|fixed)\b|\bno (?:current )?shared-cache race\b/i.test(adapterAssessment);
  const ids: Seed[] = [];
  // The inventory alias needs its own current action; an inline quoted title
  // or actions reproduced only as source material cannot establish this seed.
  const inventoryProse = prose(q.question, true)
    .replace(/(\b(?:this|the) class[ -]inventory decision is )['"“](withdrawn|rejected|cancelled|canceled|resolved)['"”]/gi, '$1$2')
    .replace(/"[^"\n]*"|“[^”\n]*”/g, '');
  const inventoryAction = q.options.some(o => {
    const label = prose(o.label, true), description = prose(o.description ?? '', true).replace(/"[^"\n]*"|“[^”\n]*”/g, '');
    return /^(?:[A-D][).:—–-]\s*)?(?:reduce|cut|simplify|remove|collapse|merge)\b[^.!?\n]{0,160}\b(?:classes|types|abstractions)\b/i.test(label)
      && !/^(?:source|quoted|historical|example|if approved|hypothetical)\b|\b(?:this|the) (?:option|action|remedy) is (?:withdrawn|rejected|cancelled|canceled)\b/i.test(description);
  });
  const classInventory = /^(?:D[1-9]\d*\s*[—–:-]\s*)?(?:Reduce|Simplify|Trim) the class inventory(?: before building)?\?$/i.test(prose(subject, true))
    && inventoryAction && !/\b(?:this|the) class[ -]inventory decision (?:is|was|has been) (?:withdrawn|rejected|cancelled|canceled|resolved|not current)\b/i.test(inventoryProse);
  if (classInventory || /\b(?:scope|complexity|classes|types|abstractions)\b/i.test(title) &&
      /\b(?:files|classes|types|abstractions)\b/i.test(title) &&
      action(/\b(?:reduce|cut|simplify|remove|collapse|merge|pure function)\b/i)) ids.push('complexity');
  if ((sharedAdapter || /\b(?:AuthCache|cache)\b/i.test(title) &&
      /\b(?:global|module[ -]level|mutab\w*|both|shar\w*|ownership|writers|same\s+(?:AuthCache|cache))\b/i.test(title)) &&
      action(/\b(?:inject\w*|DI|serializ\w*|single[ -]writer|ownership|composition root)\b/i)) ids.push('shared-cache');
  if (/\b(?:validateAndDispatch|catch\w*)\b/i.test(title) &&
      /\b(?:swallow\w*|nested|silent\w*|hidden|suppres\w*)\b/i.test(title) &&
      action(/\b(?:split|rethrow|typed|flatten|propagat\w*)\b/i)) ids.push('swallowed-errors');
  if (/\b(?:sequential|parallel\w*|Promise\.all(?:Settled)?)\b/i.test(title) &&
      /\b(?:IDP|identity provider)\b/i.test(prose(q.question)) &&
      action(/\b(?:parallel\w*|Promise\.all(?:Settled)?)\b/i)) ids.push('sequential-idp');
  return ids.length ? ids : explainedSeedSubjects(q);
}

/** A decision may put its current defect in its own metadata/ELI10, not its title. */
function explainedSeedSubjects(q: NativePlanQuestionCall['questions'][number]): Seed[] {
  const rawTitle = q.question.split('\n').find(line => line.trim())?.trim() ?? '';
  const ordinal = /^D([1-9]\d*)\s*[—–:-]/.exec(rawTitle)?.[1];
  const owner = `(?:(?:this|the|that) (?:finding|issue|decision|gap|defect|assessment|explanation|option|action|remedy)${ordinal ? `|D${ordinal}` : ''})`;
  const inactive = '(?:withdrawn|retracted|rejected|cancelled|canceled|resolved|fixed|superseded|optional|hypothetical|unproven|not current|no longer current)';
  const current = (value: string) => prose(value.replace(/\*\*/g, '').replace(
    new RegExp(`(${owner} (?:is|was|has been) )["“'‘\x60](${inactive})["”'’\x60]`, 'gi'), '$1$2'), true)
    .replace(/"[^"]*"|“[^”]*”|(?<!\w)'[^'\n]*'(?!\w)|‘[^’]*’/g, '');
  const framed = /(?:^|[.!?;:]\s+|\n)(?:(?:Project\/branch\/task|ELI10):\s*)?(?:source|quoted|historical|example|hypothetical|if approved|once approved|when approved|pending approval|assuming approval|provided approval)\b/i;
  const active = (value: string) => !framed.test(value)
    && !/\b(?:copied|quoted|historical)\s+(?:(?:source|quoted)\s+)?(?:example|excerpt|text|material)\b/i.test(value)
    && !new RegExp(`\\b${owner} (?:is|was|has been) ${inactive}\\b`, 'i').test(value)
    && !/\b(?:if|once|when|unless) (?:approved|accepted)|\b(?:after|pending) approval\b/i.test(value)
    && !/(?:^|[.!?;]\s+|\n)(?:Correction:\s*)?(?:do not|don't|never|skip|cancel|withdraw) (?:reduce|cut|remove|keep|flatten|split|map|rethrow|parallelize|run|apply)\b/i.test(value);
  // Inline literal sentences and a non-current title cannot own the packet.
  if (/^[`"“>]/.test(rawTitle.replace(/^D[1-9]\d*\s*[—–:-]\s*/, ''))) return [];
  const text = current(q.question), lines = text.split('\n').filter(line => line.trim());
  const explanations = lines.filter(line => /^ELI10:/.test(line));
  const metadata = lines.filter(line => /^Project\/branch\/task:/.test(line));
  const explanationIndex = /^\[P[0-3]\] /.test(lines[2] ?? '') ? 3 : 2;
  if (explanations.length !== 1 || metadata.length !== 1 || lines[1] !== metadata[0] || lines[explanationIndex] !== explanations[0]
      || explanationIndex === 3 && !active(lines[2]!.replace(/^\[P[0-3]\] /, ''))
      || !/^Project\/branch\/task: \S/.test(metadata[0]!) || !active(text)) return [];
  const title = lines[0]!.replace(/^D[1-9]\d*\s*[—–:-]\s*/, '');
  if (!active(title)) return [];
  const explanation = explanations[0]!, subject = metadata[0] + ' ' + explanation;
  const options = q.options.map(o => current(`${o.label}\n${o.description ?? ''}`)).filter(active);
  const ids: Seed[] = [];
  // Step 0 may name the complexity decision in its title and put the concrete
  // inventory in its own explanation. The reduction and retained backing
  // store must belong to one current option, opposed by that same inventory.
  if (/^(?:Step 0 )?complexity (?:check|decision):\s*(?:reduce|simplify|trim)\b/i.test(title)) {
    const fileCounts = [...explanation.matchAll(/\b(?:touches|changes|modifies|spans) ([1-9]\d*) files\b/gi)];
    const inventories = [...explanation.matchAll(/\b(?:adds|introduces) ([1-9]\d*) (?:new )?(?:classes|types) \(([^)]+)\)/gi)];
    const names = inventories[0]?.[2]?.split(/,\s*(?:and )?| and /) ?? [];
    const conditional = /\b(?:this|the|that) (?:finding|issue|decision|option|action|remedy) (?:(?:applies|proceeds|will proceed) (?:only )?(?:if|once|when)|(?:is|was|has been) conditional on (?:user )?approval)\b|(?:^|\n|[.!?;]\s+)(?:(?:ELI10|Project\/branch\/task):\s*)?(?:if|once|when|assuming|provided) (?:the )?(?:user|owner|reviewer) (?:approves|agrees|accepts)\b/i;
    const currentOptions = options.filter(o => !conditional.test(o));
    if (fileCounts.length === 1 && inventories.length === 1 && names.length === Number(inventories[0]![1])
        && new Set(names).size === names.length && (Number(fileCounts[0]![1]) >= 8 || names.length >= 2)
        && ['TokenStore', 'SessionMint', 'AuthCache', 'RequestPolicy'].every(name => names.includes(name)) && /\bAuthBroker\b/.test(explanation)
        && /\b(?:existing|current) (?:cache )?adapter (?:already )?keys tokens by tenant\b[^.!?]{0,40}\bevicts?\b[^.!?]{0,40}\binvalidates?\b/i.test(explanation)
        && /\bAuthCache (?:is|remains) (?:just |only )?a facade (?:over (?:it|the (?:existing |current )?(?:cache )?adapter)|for (?:that|the) adapter)\b/i.test(explanation)
        && /\bTokenStore (?:looks like|is|adds) (?:a |another )?(?:second|duplicate) (?:token )?store\b|\bTokenStore duplicates (?:the )?(?:existing |current )?adapter(?:'s)? token storage\b/i.test(explanation)
        && /\bRequestPolicy\b[^.!?]{0,90}\b(?:currently )?(?:has|serves) (?:only )?(?:one|a single) consumer\b/i.test(explanation)
        && !conditional.test(text)
        && !/\bTokenStore (?:now |already )?has (?:a documented )?independent purpose|\bRequestPolicy (?:now |already )?has (?:two|multiple|a second) consumers?\b/i.test(text)
        && currentOptions.some(o => /^(?:[A-D][):.]\s*)?(?:Reduce:\s*)?(?:cut|remove|drop) TokenStore\b/i.test(o)
          && /\b(?:demote|inline|flatten) RequestPolicy\b|\b(?:make|turn) RequestPolicy (?:into )?(?:a )?(?:plain|pure) function\b/i.test(o)
          && /\b(?:one|single|only) (?:(?:token|backing) )?(?:store|storage layer|cache)\b[^.!?\n]{0,80}\b(?:existing|current) (?:cache )?adapter\b|\b(?:existing|current) (?:cache )?adapter (?:as|is|remains|provides) (?:the )?(?:one|single|only) (?:(?:token|backing) )?(?:store|storage layer|cache)\b/i.test(o)
          && /\bAuthCache\b/.test(o))
        && currentOptions.some(o => /^(?:[A-D][):.]\s*)?(?:Proceed as-is|keep|retain)\b/i.test(o)
          && new RegExp(`\\b${inventories[0]![1]} (?:new )?(?:classes|types)\\b`, 'i').test(o)
          && new RegExp(`\\b${fileCounts[0]![1]} files\\b`, 'i').test(o)
          && /\b(?:two|2|separate) invalidation (?:paths|stories)\b/i.test(o))) ids.push('complexity');
  }
  // The overlapping stores, reduced component count and single backing store
  // must be this question's finding and one option's complete repair.
  if (/\b(?:scope|components?|pieces|classes|decomposition)\b/i.test(title)
      && ['AuthBroker', 'SessionMint', 'AuthCache', 'TokenStore'].every(name => subject.includes(name))
      && /\b(?:plan (?:adds|builds)|new)\b/i.test(explanation)
      && /\b(?:all|both) store tokens\b|\b(?:overlapping|redundant|duplicate) (?:token )?(?:stores|caches|storage)\b/i.test(explanation)
      && !/\b(?:now|already) (?:have|has) (?:independent|distinct)|\b(?:no longer|not) (?:overlapping|redundant|duplicate)\b/i.test(text)
      && options.some(o => /^(?:[A-D][):.]\s*)?(?:reduce|cut|remove|drop|fewer|simplify)\b/i.test(o)
        && /\b(?:keep|retain) AuthBroker\b/i.test(o) && /\bSessionMint\b/.test(o)
        && /\binjected AuthCache\b|\binject(?:ed)? (?:the )?(?:existing |shared )?(?:cache )?adapter\b/i.test(o)
        && /\b(?:one|single) (?:backing store|cache|storage layer)\b/i.test(o))) ids.push('complexity');
  if (/\bvalidateAndDispatch\b/.test(title)
      && /\bcatch(?:es)?\b[^.!?]{0,100}\bswallow\w*\b[^.!?]{0,60}\b(?:error|failure)/i.test(subject)
      && /\b(?:quietly|silent|nothing is logged|keeps? going|carries on)\b/i.test(explanation)
      && !/\bvalidateAndDispatch\(\) (?:now |already )?(?:rethrows every error|no longer swallows failures)\b/i.test(text)
      && options.some(o => /\b(?:flatten|split|named helpers)\b/i.test(o)
        && /\b(?:typed (?:error )?boundary|one (?:error )?(?:boundary|catch))\b/i.test(o)
        && /\bmaps?\b[^.!?]{0,140}\b(?:[45]\d\d|response|outcome)/i.test(o)
        && /\brethrows? (?:unknowns|unknown errors)|\bpropagates? (?:unknown|all) (?:errors|failures)\b/i.test(o))) ids.push('swallowed-errors');
  if (/\b(?:IDP|identity provider) calls?\b/i.test(title)
      && /\bsequential\b[^.!?]{0,60}\b(?:IDP|identity provider) calls?\b/i.test(metadata[0]!)
      && /\bindependent\b/i.test(metadata[0]!)
      && /\b(?:at once|parallel\w*|concurrent\w*)\b/i.test(explanation)
      && !/\b(?:calls|requests) (?:are |now |already )*(?:parallel|concurrent|no longer sequential)\b/i.test(text)
      && options.some(o => /\b(?:Promise\.all|paralleliz\w*|concurrent\w*)\b/i.test(o)
        && /\b(?:calls|requests|siblings)\b/i.test(o))) ids.push('sequential-idp');
  return ids;
}

function completedDecision(call: NativePlanQuestionCall, startedAt: number, finishedAt: number): boolean {
  const answeredAt = Date.parse(call.answeredAt ?? '');
  if (!call.sessionId || !call.toolUseId || call.answered !== true || call.failed !== false ||
      !Number.isFinite(answeredAt) || answeredAt < startedAt || answeredAt > finishedAt ||
      call.questions.length < 1 || call.questions.length > 4 || !Array.isArray(call.unansweredQuestionIndices) ||
      call.unansweredQuestionIndices.length !== 0) return false;
  return new Set(call.questions.map(q => q.question)).size === call.questions.length &&
    Object.keys(call.answers ?? {}).length === call.questions.length &&
    call.questions.every(q => q.question.trim() && !q.multiSelect && q.options.length >= 2 && q.options.length <= 4 &&
    q.options.every(o => o.label.trim()) && new Set(q.options.map(o => o.label)).size === q.options.length &&
    q.options.some(o => call.answers?.[q.question] === o.label));
}

/** Structural eligibility for this distinct-issue counter, not seed quality. */
function batchingIssueNumber(call: NativePlanQuestionCall): string | undefined {
  if (!completedDecision(call, 0, Date.now()) || call.questions.length !== 1) return;
  const q = call.questions[0]!;
  const issue = /^(?:D[1-9]\d*\s*[—–:-]\s*)?Issue ([1-9]\d*)\s*:\s*\S[^\n]*$/i.exec(q.question.split('\n')[0]!)?.[1];
  if (!issue || !new RegExp(`^(?:Arch(?:itecture)?|Code quality|Tests?|Testing|Performance|Security)(?: ${issue})?$`, 'i').test(q.header.trim())) return;
  const optionIds = q.options.map(o => /^([1-9]\d*)([A-D])[.):]\s+\S/i.exec(o.label));
  if (optionIds.some(id => id?.[1] !== issue) || new Set(optionIds.map(id => id![2]!.toUpperCase())).size !== q.options.length) return;
  // Owned scalar statuses remain current prose; a whole code example does not.
  const owner = `(?:(?:this|the|that) (?:issue|finding|decision)|Issue ${issue})`;
  const statusPrefix = `(?:^|[.!?;]\\s+|\\n)(?:Correction:\\s*)?${owner} (?:is|was|has been) `;
  const scalarOwner = new RegExp(`${statusPrefix}$`, 'i');
  const text = q.question.replace(/`([^`\n]+)`/g, (span, body: string, at: number, source: string) =>
    scalarOwner.test(source.slice(0, at)) ? body : span);
  const inactive = new RegExp(`${statusPrefix}["“'‘]?(?:withdrawn|cancelled|canceled|rejected|superseded|resolved|closed|hypothetical|not current|no longer current)\\b`, 'i');
  return inactive.test(prose(text, true)) ? undefined : issue;
}

/** Batching measures separate native issue decisions; seed quality is checked separately. */
export function isEngBatchingIssueAUQ(fp: AskUserQuestionFingerprint, priorCalls: readonly NativePlanQuestionCall[] = []): boolean {
  const call = fp.nativeCall;
  if (!call || fp.signature !== `${call.sessionId}:${call.toolUseId}` ||
      (fp.nativeQuestionIndex !== undefined && fp.nativeQuestionIndex !== 0) ||
      priorCalls.some(prior => prior.sessionId !== call.sessionId || prior.toolUseId === call.toolUseId)) return false;
  const issue = batchingIssueNumber(call);
  if (!issue) return false;
  const q = call.questions[0]!;
  if (fp.options.length !== q.options.length || !fp.options.every((o, i) => o.index === i + 1 && o.label === q.options[i]!.label)) return false;
  // Re-asking an eligible issue cannot inflate the floor; setup and batches do not suppress later separate decisions.
  return !priorCalls.some(prior => batchingIssueNumber(prior) === issue);
}

/** A named required test can specify characterization without an "Add" prefix. */
function requiredLegacyCharacterization(task: string): boolean {
  const text = task.replace(/\s+/g, ' ');
  return /^legacyAuthFlow(?:\(\))?\s+(?:regression|characterization)\s+tests?\.\s+Before\s+(?:the\s+)?(?:rewrite|refactor|change),\s+(?:capture|pin|record)\s+(?:the\s+)?(?:current|existing|prior)\b[^.;!?]{0,240}\bbehavior\s+of\s+legacyAuthFlow(?:\(\))?\b[^.;!?]*\.\s+The\s+rewritten\s+(?:path|flow|implementation)\s+must\s+pass\s+the\s+same\s+assertions\./i.test(text)
    && !/["“”]|\b(?:not|never|skip\w*|defer\w*|maybe|might|could|if|unless|optional|hypothetical|unproven)\b/i.test(text)
    && !/\bno\s+(?:(?:regression|characterization)\s+)?(?:tests?|fixtures?)\s+(?:are\s+)?(?:needed|required)\b/i.test(text);
}

/** Required suites bind a numbered task to an untouched legacy baseline or parity oracle. */
function declaredLegacyCharacterization(text: string): boolean {
  const sections: Array<{ title: string; body: string[]; asserted: boolean }> = [];
  const owners: Array<{ level: number; asserted: boolean }> = [];
  let preamble = '', sourcePreamble = false;
  const sourceFrame = (body: string) => {
    const text = body.replace(/"[^"\n]*"|“[^”\n]*”/g, '').replace(/\s+/g, ' ');
    return /\b(?:(?:hypothetical|historical) example|unproven hypothesis|(?:source|quoted) (?:material|text) only|(?:are|is) not requirements? of this plan)\b/i.test(text)
      || /^\s*(?:(?:quoted )?source(?: (?:excerpt|text|material))?|(?:historical|earlier|previous) (?:review )?assessment):(?:\s|$)/i.test(text);
  };
  for (const line of prose(text).split('\n')) {
    const heading = /^(#{1,6})\s+(.+)$/.exec(line);
    if (heading) {
      while (owners.length && owners.at(-1)!.level >= heading[1]!.length) owners.pop();
      if (/^Current reviewed plan$/i.test(heading[2]!) && owners.length === 0) sourcePreamble = false;
      const asserted = !sourcePreamble && owners.every(owner => owner.asserted)
        && !/\b(?:source|example|hypothetical|proposed|optional|quoted|historical|template|unproven)\b/i.test(heading[2]!);
      owners.push({ level: heading[1]!.length, asserted });
      sections.push({ title: heading[2]!, body: [], asserted });
    } else if (sections.length) {
      const section = sections.at(-1)!;
      section.body.push(line);
      if (sourceFrame(section.body.join(' '))) section.asserted = owners.at(-1)!.asserted = false;
    } else {
      preamble += ' ' + line;
      sourcePreamble = sourceFrame(preamble);
    }
  }
  const current = sections.filter(section => section.asserted);
  const mandatory = current.filter(section => /^CRITICAL regression \(mandatory, regression rule\)$/i.test(section.title));
  const declaration = /^legacyAuthFlow(?:\(\))? is (?:existing|current) behavior being (?:modified|refactored)\b[^!?]{0,240}\.\s+(?:A|The) characterization test suite for legacyAuthFlow(?:\(\))? is (?:added|required) as a (?:critical|mandatory) requirement:\s*(?:capture|pin|record) (?:current|existing|prior)\b[^.!?]{1,400}\.\s+This suite runs against the flag-OFF path and is the oracle the new path is compared to during rollout\./i;
  const withdrawn = (body: string, task?: string) => new RegExp(
    `\\b(?:${task ? `${task}|` : ''}(?:this|the|that)\\s+(?:(?:characterization|regression|contract)\\s+)?(?:suite|task|test|requirement)|(?:characterization|regression)\\s+(?:suite|tests?))\\s+(?:(?:is|was|has been)\\s+)?(?:(?:not|no longer)\\s+(?:required|needed)|cancelled|canceled|withdrawn|rejected|deferred|optional)\\b`, 'i').test(body)
    || /\b(?:do not|never|skip|defer|cancel|withdraw)\s+(?:run(?:ning)?\s+)?(?:the|this)\s+(?:characterization\s+)?suite\b/i.test(body);
  const declared = mandatory.some(section => {
    const body = section.body.join(' ').replace(/\s+/g, ' ').trim();
    const claim = declaration.exec(body)?.[0];
    return claim && !/["“”]|\b(?:maybe|might|could|if|unless|optional|hypothetical|unproven)\b/i.test(claim)
      && !withdrawn(body);
  });
  if (declared) for (const section of current.filter(s => s.title === 'Implementation Tasks')) {
    const tasks = section.body.join('\n').split(/\n(?=-\s)/);
    for (const task of tasks) {
      const match = /^\s*-\s+(?:\[[ xX]\]\s*)?(T[1-9]\d*)(?:\s+\([^\n)]*\))?\s+[—–:-]\s+(?:[A-Za-z][\w-]*(?:\/[A-Za-z][\w-]*)+(?:\s+tests)?\s+[—–]\s+)?CRITICAL regression:\s+characterization suite for legacyAuthFlow(?:\(\))? prior behavior[\t ]*(?:\n|$)/i.exec(task);
      if (!match || withdrawn(task, match[1])) continue;
      const baseline = new RegExp(`^[1-9]\\d*\\. Run the characterization suite \\(${match[1]}\\) against the untouched legacyAuthFlow(?:\\(\\))? first and commit it green\\. This is the baseline\\.`, 'i');
      if (current.some(s => s.title === 'Verification' && baseline.test(s.body.join(' ').replace(/\s+/g, ' ').trim())
        && !withdrawn(s.body.join(' '), match[1]))) return true;
    }
  }
  for (const section of current.filter(s => /^CRITICAL: regression contract test for legacyAuthFlow\(\) \(iron rule, no decision needed\)$/.test(s.title))) {
    const body = section.body.join(' ').replace(/\s+/g, ' ').trim();
    const parity = /^The rewrite modifies existing behavior with no covering test \([^)]{1,120}\)\. Add ([A-Za-z][\w/-]*\.contract\.test\.[jt]s): a fixture table of \(tenant, token, policy\) cases covering [^.!?]{1,300}\. Run each fixture through legacyAuthFlow\(\) and ([A-Za-z][\w]*)\.authenticate\(\) and assert identical ([A-Za-z][\w]*) shape on success and identical error code on failure\. This test is also the gate for flipping any tenant's flag and for TODO [1-9]\d* removal\./.exec(body);
    if (!parity || withdrawn(body) || /["“”]|\b(?:maybe|might|could|if|unless|optional|hypothetical|unproven)\b/i.test(parity[0])) continue;
    const unchanged = current.some(s => {
      if (!s.title.endsWith(`: Per-tenant flag routes legacy vs ${parity[2]}`)
        || !/^Issue [1-9]\d* \(D[1-9]\d*, chose [1-9]\d*[A-D]\): /.test(s.title)) return false;
      const body = s.body.join('\n');
      const release = /(?:^|\n)- A tenant-keyed flag [A-Za-z][\w.]*\[tenantId\] \(default off\) selects the path at the\s+login entry point\. legacyAuthFlow\(\) stays callable and unchanged this release\./.exec(body);
      const prefix = release ? body.slice(0, release.index).trim().split(/\n\s*\n/).at(-1) ?? '' : '';
      return Boolean(release) && !/^(?:if|unless|maybe|perhaps|proposed|optional)\b/i.test(prefix)
        && !/\blegacyAuthFlow(?:\(\))?\s+(?:(?:is|was|will be|has been)\s+)?(?:changed|modified|rewritten|removed|withdrawn|not unchanged|no longer unchanged)\b/i.test(s.body.join(' '));
    });
    if (!unchanged) continue;
    for (const tasks of current.filter(s => s.title === 'Implementation Tasks')) {
      for (const task of tasks.body.join('\n').split(/\n(?=-\s)/)) {
        const match = /^\s*-\s+(?:\[[ xX]\]\s*)?(T[1-9]\d*)(?:\s+\([^\n)]*\))?\s+[—–:-]\s+Tests\s+[—–]\s+CRITICAL regression contract test: same fixtures through legacyAuthFlow\(\) and ([A-Za-z][\w]*), identical ([A-Za-z][\w]*) \/ error codes[\t ]*(?:\n|$)/.exec(task);
        if (!match || match[2] !== parity[2] || match[3] !== parity[3] || withdrawn(task, match[1])) continue;
        const files = /^\s+- Files: ([^\n]+)$/m.exec(task);
        if (files?.[1] === parity[1] && /^\s+- Verify: contract suite green on both paths[\t ]*$/m.test(task)) return true;
      }
    }
  }
  // A mandatory snapshot can state the legacy oracle as a required test
  // list item, then bind it to the numbered task's unchanged-code verification.
  const snapshotSource = prose(text, true).replace(/\s+/g, ' ');
  const unquoted = (body: string) => body.replace(/"[^"\n]*"|“[^”\n]*”/g, '');
  const suiteWithdrawn = current.some(s => {
    // A named foreign suite owns its generic withdrawal; it cannot cancel
    // the legacy obligation in another section of the same report.
    const namedSuite = /^(.*?)\b(?:regression|characterization)\s+(?:suite|tests?)\b/i.exec(s.title);
    const foreignSuite = Boolean(namedSuite?.[1]?.trim() && !/^(?:legacy(?:AuthFlow(?:\(\))?)?|final|current|updated)[\s:—–-]*$/i.test(namedSuite[1]));
    return unquoted(s.body.join('\n')).split(/\n|[.!?]\s+/).some(statement => {
      const subject = /^(?:Correction:\s*)?(?:the|this|that)\s+(legacy\s+)?(?:regression|characterization)\s+(?:suite|tests?)\b/i.exec(statement.trim());
      return Boolean(subject && (!foreignSuite || subject[1]) && withdrawn(statement));
    });
  });
  for (const section of current.filter(s => /^Required tests(?: \([^\n]*\))?$/i.test(s.title))) {
    const body = section.body.join('\n').trim();
    if (!body.startsWith('- ')) continue;
    for (const block of body.split(/\n(?=-\s)/)) {
      const claim = block.replace(/\s+/g, ' ').trim();
      if (suiteWithdrawn || !/^- CRITICAL regression legacyAuthFlow(?:\(\))? snapshot: capture current outputs for [^;.!?]{1,240} BEFORE any change; assert both legacy \(flag OFF\) and new \(flag ON\) paths produce identical observable results\. Mandatory under the coverage-audit regression rule\./.test(claim)
          || !snapshotSource.includes(claim) || withdrawn(unquoted(claim))
          || /["“”]|\b(?:not|never|maybe|might|could|if|unless|optional|hypothetical|unproven)\b/i.test(claim)) continue;
      for (const tasks of current.filter(s => s.title === 'Implementation Tasks')) {
        const body = tasks.body.join('\n').trim();
        const taskPrefix = body.split(/\n(?=-\s)/)[0]?.trim() ?? '';
        if (!body.startsWith('- ') && (!/^Synthesized from (?:this|the) review's findings\./.test(taskPrefix)
            || /\b(?:if|unless|optional|hypothetical|example|source|quoted|unproven)\b/i.test(taskPrefix))) continue;
        for (const task of body.split(/\n(?=-\s)/)) {
          const match = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–] [A-Za-z][\w-]*(?:\/[A-Za-z][\w-]*)+ [—–] Snapshot legacyAuthFlow\(\) behavior as regression tests before any change[\t ]*(?:\n|$)/.exec(task);
          if (!match || !snapshotSource.includes(task.replace(/\s+/g, ' ').trim())
              || !/^\s+- Verify: tests pass against unmodified legacy code, then against flag-OFF route[\t ]*$/m.test(task)
              || withdrawn(unquoted(task).replace(/\b(?:this|that|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement'), match[1])) continue;
          const taskWithdrawal = new RegExp(`\\b${match[1]}\\s+(?:is|was|has been)\\s+(?:cancelled|canceled|withdrawn|rejected|deferred|optional|not required|no longer required)\\b`, 'i');
          if (!current.some(s => taskWithdrawal.test(unquoted(s.body.join('\n'))))) return true;
        }
      }
    }
  }
  // A mandatory declaration can require capture before touching the legacy
  // function, with a task and ordered verification on both router settings.
  const sourceOwner = (body: string) => sourceFrame(body) ||
    /\b(?:is|was|presents?|represents?)\s+(?:(?:only|just)\s+)?(?:an?\s+)?(?:quoted|hypothetical|historical|example|template)\b/i.test(body);
  const conditionalOwner = (prefix: string) => /^(?:if|unless|maybe|perhaps|proposed|optional)\b/i.test(prefix.trim().split('\n').at(-1)?.trim() ?? '');
  for (const section of current.filter(s => /^REGRESSION \(mandatory rule, no approval needed\) [—–-] CRITICAL$/i.test(s.title))) {
    const body = unquoted(section.body.join(' ')).replace(/\s+/g, ' ').trim();
    const declaration = /(?:^|[.!?]\s+)Add a characterization (?:test )?suite for legacyAuthFlow\(\) before (?:touching|changing|refactoring) it:\s*(?:capture|pin|record) current inputs and outputs \([^()!?]{1,300}\) and run the same suite against ([A-Za-z][\w]*) on both flag settings\. A behavior difference between paths is a test failure\b/i.exec(body);
    if (!declaration || suiteWithdrawn || withdrawn(body) ||
        !snapshotSource.includes(declaration[0].trim()) || sourceOwner(body.slice(0, declaration.index)) ||
        /\b(?:if|unless|maybe|might|could|proposed|optional|hypothetical|unproven)\b/i.test(body.slice(0, declaration.index))) continue;
    for (const section of current.filter(s => s.title === 'Implementation Tasks')) {
      const taskBody = section.body.join('\n').trim();
      const taskPrefix = taskBody.split(/\n(?=-\s)/)[0]?.trim() ?? '';
      if (!taskBody.startsWith('- ') && (!/^Synthesized from (?:this|the) review's findings\./.test(taskPrefix) ||
          /\b(?:if|unless|optional|hypothetical|example|source|quoted|unproven)\b/i.test(taskPrefix))) continue;
      for (const task of taskBody.split(/\n(?=-\s)/)) {
        const match = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] [A-Za-z][\w-]*(?:\/[A-Za-z][\w-]*)+ [—–-] CRITICAL characterization suite for legacyAuthFlow\(\), run on both router paths[\t ]*(?:\n|$)/i.exec(task);
        const verify = /^\s+- Verify: suite passes on legacy before any refactor; passes on new path before flag enable[\t ]*$/m.exec(task);
        const taskIntro = unquoted(taskBody.slice(0, taskBody.indexOf(task))).trim().split('\n').at(-1) ?? '';
        if (!match || !verify || !snapshotSource.includes(task.replace(/\s+/g, ' ').trim()) ||
            conditionalOwner(taskIntro) || sourceOwner(taskIntro) || conditionalOwner(task.slice(0, verify.index)) || sourceOwner(unquoted(task.slice(0, verify.index))) ||
            withdrawn(unquoted(task).replace(/\b(?:this|that|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement'), match[1])) continue;
        const taskWithdrawal = new RegExp(`\\b${match[1]}\\s+(?:is|was|has been)\\s+(?:cancelled|canceled|withdrawn|rejected|deferred|optional|not required|no longer required)\\b`, 'i');
        if (current.some(s => taskWithdrawal.test(unquoted(s.body.join('\n'))))) continue;
        for (const verification of current.filter(s => /^Verification(?: \([^\n]*\))?$/i.test(s.title))) {
          const body = unquoted(verification.body.join('\n')).trim();
          const baseline = /^([1-9]\d*)\. Run the characterization suite against legacyAuthFlow\(\) on the unmodified code; it must pass before any refactor lands\.[\t ]*$/m.exec(body);
          const compare = new RegExp(`^([1-9]\\d*)\\. Run the characterization suite through ${declaration[1]} with the flag on new; zero differences\\.[\\t ]*$`, 'm').exec(body);
          if (baseline && compare && Number(baseline[1]) < Number(compare[1]) && baseline.index < compare.index &&
              !conditionalOwner(body.slice(0, baseline.index)) && !conditionalOwner(body.slice(0, compare.index)) &&
              !sourceOwner(body.slice(0, baseline.index)) && !sourceOwner(body.slice(0, compare.index)) &&
              !withdrawn(body.replace(/\b(?:this|that|the)\s+(?:baseline|verification)\b/gi, 'this requirement'), match[1]) &&
              snapshotSource.includes(baseline[0]) && snapshotSource.includes(compare[0])) return true;
        }
      }
    }
  }
  // A golden-master requirement names the existing output oracle, then ties
  // its capture task to an untouched baseline and reruns after later tasks.
  const goldenSourceOwner = (body: string) => sourceOwner(body) || /(?:^|\n)\s*(?:Source|Quoted source) excerpt:\s*(?:\n|$)/i.test(body);
  // A staged refactor can bind its baseline and parity checks to two tasks,
  // with the release labels separate from their task identities.
  const staged = current.filter(s => /^REGRESSION \(CRITICAL, mandatory\)$/i.test(s.title));
  const taskSections = current.filter(s => s.title === 'Implementation Tasks');
  if (!suiteWithdrawn && staged.length === 1 && taskSections.length === 1) {
    const stagedSource = (value: string) => goldenSourceOwner(unquoted(value)) ||
      /(?:^|\n)\s*(?:Source|Quoted source|Earlier review assessment):/i.test(unquoted(value));
    const stagedConditional = (value: string) => conditionalOwner(value) ||
      /(?:^|\n)\s*(?:assuming|provided)\b/i.test(unquoted(value));
    const body = unquoted(staged[0]!.body.join(' ')).replace(/\s+/g, ' ').trim();
    const declaration = /^(?:[A-Za-z][\w./-]*:[1-9]\d*(?:-[1-9]\d*)? [—–-]\s*)?This is existing behavior being modified with no covering test\. (PR[1-9]\d*) adds characterization tests that pin every observable outcome of legacyAuthFlow\(\) \(([^()!?]{1,600})\) before any rewrite\. They run against the legacy path in \1, against both paths in (PR[1-9]\d*), and are folded into pipeline tests in (PR[1-9]\d*)\. Pre-authorized by the regression rule\.$/.exec(body);
    const tasksText = taskSections[0]!.body.join('\n').trim();
    const taskBlocks = tasksText.split(/\n(?=-\s)/);
    const ids = taskBlocks.map(t => /^- (?:\[[ xX]\] )?(T[1-9]\d*)\b/.exec(t)?.[1]).filter(Boolean);
    const taskPrefix = taskBlocks[0]!.startsWith('- ') ? '' : taskBlocks[0]!;
    if (declaration && Number(declaration[1]!.slice(2)) < Number(declaration[3]!.slice(2)) &&
        Number(declaration[3]!.slice(2)) < Number(declaration[4]!.slice(2)) &&
        !withdrawn(body) && !stagedSource(taskPrefix) && !stagedConditional(taskPrefix) &&
        ids.length === new Set(ids).size) {
      const baselinePattern = new RegExp(`^- (?:\\[[ xX]\\] )?(T[1-9]\\d*)(?: \\([^\\n)]*\\))? [—–-] ${declaration[1]} legacy auth [—–-] Write characterization \\(regression\\) tests pinning legacyAuthFlow\\(\\) prior behavior before any rewrite[\\t ]*(?:\\n|$)`);
      for (const baseline of taskBlocks) {
        const task = baselinePattern.exec(baseline);
        const verify = /^\s+- Verify: suite green against unmodified legacy path; ([1-9]\d*) cases recorded as oracle[\t ]*$/m.exec(baseline);
        if (!task || !verify || Number(verify[1]) !== declaration[2]!.split(',').length ||
            stagedSource(baseline) || stagedConditional(baseline.slice(0, verify.index))) continue;
        const parityPattern = new RegExp(`^- (?:\\[[ xX]\\] )?(T[1-9]\\d*)(?: \\([^\\n)]*\\))? [—–-] ${declaration[3]} strangler fig [—–-] Make legacyAuthFlow delegate to the new pipeline behind a feature flag; ${task[1]} characterization tests pass against both paths[\\t ]*(?:\\n|$)`);
        for (const parity of taskBlocks) {
          const rerun = parityPattern.exec(parity);
          const parityVerify = new RegExp(`^[\\t ]+- Verify: ${task[1]} suite green with flag on and off[\\t ]*$`, 'm').exec(parity);
          if (!rerun || task[1] === rerun[1] || !parityVerify || taskBlocks.indexOf(baseline) >= taskBlocks.indexOf(parity) ||
              stagedSource(parity) || stagedConditional(parity.slice(0, parityVerify.index))) continue;
          // Quoted old prose is evidence about history. A quoted status word
          // with a current task/suite subject still cancels its obligation.
          const status = (value: string) => unquoted(value.replace(new RegExp(`((?:${task[1]}|${rerun[1]})(?: (?:verification|baseline verification|rerun))? (?:is|was|has been) |(?:this|the) (?:legacy )?(?:(?:characterization|regression|baseline|unchanged-code) )?(?:suite|requirement|verification) (?:is|was|has been) )["“'](withdrawn|rejected|cancelled|canceled|superseded|optional|not current|no longer required)["”']`, 'gi'), '$1$2'));
          const canceled = new RegExp(`\\b(?:${task[1]}|${rerun[1]})(?: (?:verification|baseline verification|rerun))? (?:is|was|has been) (?:withdrawn|rejected|cancelled|canceled|superseded|optional|not current|no longer required)\\b`, 'i');
          const changedFirst = new RegExp(`^(?:Correction:\\s*)?legacyAuthFlow\\(\\) (?:is|was|has been|will be) (?:modified|changed|rewritten|refactored) before ${task[1]}\\b`, 'i');
          const noRerun = new RegExp(`\\b${rerun[1]} (?:no longer|does not|will not) (?:re)?runs? ${task[1]}\\b`, 'i');
          const inactive = (value: string) => withdrawn(status(value).replace(/\b(?:this|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement'), task[1]) || canceled.test(status(value)) ||
            /\b(?:this|the) (?:legacy )?(?:(?:characterization|regression|baseline|unchanged-code) )?(?:suite|requirement|verification) (?:is|was|has been) (?:superseded|not current)\b/i.test(status(value));
          if (inactive(body) || inactive(baseline) || inactive(parity) || current.some(s => {
            const assessment = status(s.body.join('\n'));
            return /\b(?:the|this) legacy (?:regression|characterization) (?:suite|tests?|requirement) (?:is|was|has been) (?:withdrawn|rejected|cancelled|canceled|superseded|optional|not current|no longer required)\b/i.test(assessment) ||
              canceled.test(assessment) || noRerun.test(assessment) ||
              assessment.split(/\n|[.!?]\s+/).some(line => changedFirst.test(line.trim()));
          })) continue;
          return true;
        }
      }
    }
  }
  const goldenWithdrawn = current.some(s => {
    const namedSuite = /^(.*?)\b(?:regression|characterization|golden[ -]master)\s+(?:suite|fixtures?|tests?)\b/i.exec(s.title);
    const foreignSuite = Boolean(namedSuite?.[1]?.trim() && !/^(?:legacy(?:AuthFlow(?:\(\))?)?|final|current|updated)[\s:—–-]*$/i.test(namedSuite[1]));
    return unquoted(s.body.join('\n')).split(/\n|[.!?]\s+/).some(statement => {
      const subject = /^(?:Correction:\s*)?(?:the|this|that)\s+(legacy(?:AuthFlow(?:\(\))?)?\s+)?golden[ -]master\s+(?:suite|fixtures?|tests?)\b/i.exec(statement.trim());
      return Boolean(subject && (!foreignSuite || subject[1]) && withdrawn(statement
        .replace(/golden[ -]master\s+(?:suite|fixtures?|tests?)/i, 'regression suite').replace(/\b(?:are|were|have been)\b/i, 'is')));
    });
  });
  for (const section of current.filter(s => /^Tests(?: \([^\n]*\))?$/i.test(s.title))) {
    const body = unquoted(section.body.join('\n')).split(/\n\s*\n/)
      .map(paragraph => paragraph.replace(/\s+/g, ' ').trim()).join('\n\n');
    const claim = /^CRITICAL \(regression rule, mandatory\): legacyAuthFlow(?:\(\))? golden[ -]master\.\s+(?:Capture|Pin|Record) current outputs for [^.!?]{1,300} BEFORE any change, assert identical behavio[u]?r after the rewrite(?: and after [^.!?]{1,120})?\./im.exec(body);
    if (!claim || suiteWithdrawn || goldenWithdrawn || withdrawn(body) ||
        !snapshotSource.includes(claim[0].replace(/\s+/g, ' ')) ||
        goldenSourceOwner(body.slice(0, claim.index)) || conditionalOwner(body.slice(0, claim.index))) continue;
    for (const tasks of current.filter(s => s.title === 'Implementation Tasks')) {
      const taskBody = tasks.body.join('\n').trim();
      const taskPrefix = taskBody.split(/\n(?=-\s)/)[0]?.trim() ?? '';
      if (!taskBody.startsWith('- ') && (!/^Synthesized from (?:this|the) review's findings\./.test(taskPrefix) ||
          /\b(?:if|unless|optional|hypothetical|example|source|quoted|unproven)\b/i.test(unquoted(taskPrefix)))) continue;
      for (const task of taskBody.split(/\n(?=-\s)/)) {
        const match = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] [A-Za-z][\w-]*(?:\/[A-Za-z][\w-]*)* [—–-] Capture golden[ -]master regression fixtures for legacyAuthFlow(?:\(\))? before any change[\t ]*(?:\n|$)/i.exec(task);
        const verify = /^\s+- Verify: fixtures pass against untouched legacy; rerun after every later task[\t ]*$/m.exec(task);
        const taskIntro = unquoted(taskBody.slice(0, taskBody.indexOf(task))).trim().split('\n').at(-1) ?? '';
        if (!match || !verify || !snapshotSource.includes(task.replace(/\s+/g, ' ').trim()) ||
            /\b(?:if|unless|optional|hypothetical|source|quoted|unproven)\b/i.test(match[0]) ||
            conditionalOwner(taskIntro) || goldenSourceOwner(taskIntro) ||
            conditionalOwner(task.slice(0, verify.index)) || goldenSourceOwner(unquoted(task.slice(0, verify.index))) ||
            withdrawn(unquoted(task).replace(/\b(?:this|that|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement'), match[1])) continue;
        const taskWithdrawal = new RegExp(`\\b${match[1]}(?:\\s+rerun)?\\s+(?:is|was|has been)\\s+(?:cancelled|canceled|withdrawn|rejected|deferred|optional|not required|no longer required)\\b`, 'i');
        if (current.some(s => taskWithdrawal.test(unquoted(s.body.join('\n'))))) continue;
        for (const verification of current.filter(s => /^Verification(?: \([^\n]*\))?$/i.test(s.title))) {
          const body = unquoted(verification.body.join('\n')).trim();
          const baseline = new RegExp(`^([1-9]\\d*)\\. Run ${match[1]} fixtures before touching anything; they must pass\\.[\\t ]*$`, 'm').exec(body);
          const rerun = new RegExp(`^([1-9]\\d*)\\. After each task, rerun the full suite plus ${match[1]} fixtures\\.[\\t ]*$`, 'm').exec(body);
          if (baseline && rerun && Number(baseline[1]) < Number(rerun[1]) && baseline.index < rerun.index &&
              !conditionalOwner(body.slice(0, baseline.index)) && !conditionalOwner(body.slice(0, rerun.index)) &&
              !goldenSourceOwner(body.slice(0, baseline.index)) && !goldenSourceOwner(body.slice(0, rerun.index)) &&
              !withdrawn(body.replace(/\b(?:this|that|the)\s+(?:baseline|verification)\b/gi, 'this requirement'), match[1]) &&
              snapshotSource.includes(baseline[0]) && snapshotSource.includes(rerun[0])) return true;
        }
      }
    }
  }
  // A current-output characterization declaration can bind the same file
  // and pre-rewrite task directly, without a separate Verification heading.
  for (const section of current.filter(s => /^REGRESSION \(mandatory, authorized by the coverage-audit regression rule [—–-] no question asked\)$/i.test(s.title))) {
    const body = unquoted(section.body.join('\n')).trim();
    const split = body.indexOf('\n- ');
    if (split < 0 || suiteWithdrawn) continue;
    const intro = body.slice(0, split).replace(/\s+/g, ' ').trim();
    if (!/^legacyAuthFlow\(\) is existing behavior being rewritten\b[^!?]{1,400}\. CRITICAL requirement added to the plan:$/.test(intro) ||
        goldenSourceOwner(intro) || /\b(?:if|unless|maybe|might|could|proposed|optional|hypothetical|unproven)\b/i.test(intro)) continue;
    const claim = body.slice(split).replace(/\s+/g, ' ').trim();
    const declaration = /^- ([A-Za-z][\w/.-]*\.test\.[jt]s) [—–-] record current outputs for: [^.!?]{1,600}\. Assert the new path \(behind the flag\) produces identical decisions and equivalent error surfaces\. These tests are written BEFORE any rewrite \((T[1-9]\d*)\) and stay green through cut-over\.$/.exec(claim);
    if (!declaration || withdrawn(body) || !snapshotSource.includes(claim) ||
        /\b(?:if|unless|maybe|might|could|proposed|optional|hypothetical|unproven)\b/i.test(claim)) continue;
    for (const section of current.filter(s => s.title === 'Implementation Tasks')) {
      const taskBody = section.body.join('\n').trim(), blocks = taskBody.split(/\n(?=-\s)/);
      const prefix = blocks[0]?.trim() ?? '';
      if (!taskBody.startsWith('- ') && (!/^Synthesized from (?:this|the) review's findings\./.test(prefix) ||
          /\b(?:if|unless|optional|hypothetical|example|source|quoted|unproven)\b/i.test(unquoted(prefix)))) continue;
      for (const task of blocks) {
        const match = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] [A-Za-z][\w/-]* [—–-] Write characterization tests for legacyAuthFlow\(\) before any rewrite[\t ]*(?:\n|$)/.exec(task);
        const file = /^\s+- Files: ([^\n]+)$/m.exec(task);
        const verify = /^\s+- Verify: suite green on current main; re-run after each later task[\t ]*$/m.exec(task);
        const beforeTask = unquoted(taskBody.slice(0, taskBody.indexOf(task))).trim().split('\n').at(-1) ?? '';
        if (!match || match[1] !== declaration[2] || file?.[1] !== declaration[1] || !verify ||
            !snapshotSource.includes(task.replace(/\s+/g, ' ').trim()) ||
            conditionalOwner(beforeTask) || goldenSourceOwner(beforeTask) ||
            conditionalOwner(task.slice(0, verify.index)) || goldenSourceOwner(unquoted(task.slice(0, verify.index))) ||
            withdrawn(unquoted(task).replace(/\b(?:this|that|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement'), match[1])) continue;
        const cancelledTask = new RegExp(`\\b${match[1]}(?:\\s+(?:rerun|verification|baseline verification))?\\s+(?:is|was|has been)\\s+(?:cancelled|canceled|withdrawn|rejected|deferred|optional|not required|no longer required)\\b`, 'i');
        const changedBeforeBaseline = new RegExp(`^(?:Correction:\\s*)?legacyAuthFlow\\(\\) (?:is|was|has been|will be) (?:modified|changed|rewritten|refactored) before ${match[1]}\\b`, 'i');
        const assessment = (body: string) => unquoted(body.replace(new RegExp(`(\\b${match[1]}(?:\\s+(?:rerun|verification|baseline verification))?\\s+(?:is|was|has been)\\s+)["“](withdrawn|rejected|cancelled|canceled)["”]`, 'gi'), '$1$2'));
        if (!current.some(s => cancelledTask.test(assessment(s.body.join('\n'))) ||
            assessment(s.body.join('\n')).split(/\n|[.!?]\s+/).some(statement => changedBeforeBaseline.test(statement.trim())))) return true;
      }
    }
  }
  // The same mandatory characterization can precede a behavior-preserving
  // extraction: its untouched baseline and the extraction's rerun share a task ID.
  const extractionSourceOwner = (body: string) => goldenSourceOwner(body) ||
    /(?:^|\n)\s*(?:(?:quoted )?source(?: (?:excerpt|text|material))?|(?:historical|earlier|previous)(?: review)?(?: assessment)?|(?:hypothetical )?example):\s*(?:\n|$)/i.test(unquoted(body));
  for (const section of current.filter(s => s.title === 'Tests')) {
    const body = unquoted(section.body.join('\n'));
    const claim = /^CRITICAL [—–-] regression rule \(mandatory, not a decision\): (T[1-9]\d*) adds a characterization test for legacyAuthFlow\(\)'s current behavior \([^\n)]{1,300}\) and lands before the ([1-9]\d*[A-D]) extraction\./m.exec(body);
    if (!claim || suiteWithdrawn || withdrawn(body, claim[1]) || !snapshotSource.includes(claim[0]) ||
        extractionSourceOwner(body.slice(0, claim.index)) || conditionalOwner(body.slice(0, claim.index))) continue;
    for (const section of current.filter(s => s.title === 'Implementation Tasks')) {
      const taskBody = section.body.join('\n').trim(), blocks = taskBody.split(/\n(?=-\s)/);
      const prefix = blocks[0]?.trim() ?? '';
      if (!taskBody.startsWith('- ') && (!/^Synthesized from (?:this|the) review's findings\./.test(prefix) ||
          extractionSourceOwner(unquoted(prefix)) || conditionalOwner(prefix))) continue;
      const active = (task: string, id: string, verifyAt: number) => {
        const beforeTask = unquoted(taskBody.slice(0, taskBody.indexOf(task))).trim().split('\n').at(-1) ?? '';
        return snapshotSource.includes(task.replace(/\s+/g, ' ').trim()) &&
          !conditionalOwner(beforeTask) && !extractionSourceOwner(beforeTask) &&
          !conditionalOwner(task.slice(0, verifyAt)) && !extractionSourceOwner(unquoted(task.slice(0, verifyAt))) &&
          !withdrawn(unquoted(task).replace(/\b(?:this|that|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement'), id);
      };
      for (const baseline of blocks) {
        const task = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] [A-Za-z][\w/-]* [—–-] Add characterization\/regression test for legacyAuthFlow\(\) current behavior[\t ]*(?:\n|$)/.exec(baseline);
        const file = /^\s+- Files: ([A-Za-z][\w/.-]*\.test\.[jt]s)$/m.exec(baseline);
        const verify = /^\s+- Verify: test passes against unmodified legacy before any other commit[\t ]*$/m.exec(baseline);
        if (!task || task[1] !== claim[1] || !file || !verify || !active(baseline, task[1], verify.index)) continue;
        for (const extraction of blocks) {
          const task2 = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] [A-Za-z][\w/-]* [—–-] Extract IDP checks \+ token validation into shared ([A-Za-z][\w]*)\(\); legacy calls it, behavior unchanged[\t ]*(?:\n|$)/.exec(extraction);
          const origin = /^\s+- Surfaced by: Code quality Issue [1-9]\d* \(D[1-9]\d*, ([1-9]\d*[A-D])\)[\t ]*$/m.exec(extraction);
          const rerun = /^\s+- Verify: (T[1-9]\d*) still green; diff to legacy is call-site only[\t ]*$/m.exec(extraction);
          if (!task2 || task2[1] === task[1] || origin?.[1] !== claim[2] || rerun?.[1] !== task[1] || !active(extraction, task2[1], rerun.index)) continue;
          const canceled = new RegExp(`\\b(?:${task[1]}|${task2[1]})(?:\\s+(?:rerun|verification|baseline verification|regression test|characterization test))?\\s+(?:is|was|has been)\\s+(?:cancelled|canceled|withdrawn|rejected|deferred|optional|not required|no longer required)\\b`, 'i');
          const changedFirst = new RegExp(`^(?:Correction:\\s*)?legacyAuthFlow\\(\\) (?:is|was|has been|will be) (?:modified|changed|rewritten|refactored) before ${task[1]}\\b`, 'i');
          const assessment = (value: string) => unquoted(value.replace(new RegExp(`(\\b(?:${task[1]}|${task2[1]})(?:\\s+(?:rerun|verification|baseline verification|regression test|characterization test))?\\s+(?:is|was|has been)\\s+)["“](withdrawn|rejected|cancelled|canceled)["”]`, 'gi'), '$1$2'));
          const rerunWithdrawn = new RegExp(`\\b${task2[1]} (?:no longer|does not|will not) reruns? ${task[1]}\\b`, 'i');
          if (!current.some(s => canceled.test(assessment(s.body.join('\n'))) || rerunWithdrawn.test(assessment(s.body.join('\n'))) ||
              assessment(s.body.join('\n')).split(/\n|[.!?]\s+/).some(line => changedFirst.test(line.trim())))) return true;
        }
      }
    }
  }

  // A golden requirement can name its parity oracle in a test-list item,
  // with the same task capturing current outputs on untouched legacy code.
  for (const section of current.filter(s => s.title === 'Test requirements')) {
    const requirements = section.body.join('\n').trim();
    for (const block of requirements.split(/\n(?=-\s)/)) {
      const claim = unquoted(block).replace(/\s+/g, ' ').trim();
      const rule = /^- CRITICAL [—–-] ([A-Za-z][\w/.-]*\/legacyAuthFlow\.regression\.test\.[jt]s) \((T[1-9]\d*), REGRESSION RULE, no approval needed\): golden tests for ([^.!?]{1,300})\./.exec(claim);
      if (!rule || suiteWithdrawn || goldenWithdrawn || !snapshotSource.includes(claim) ||
          !/(?:^|\. )These tests are the parity oracle for the D[1-9]\d* flag-off path\./.test(claim) ||
          extractionSourceOwner(block) || conditionalOwner(block) ||
          extractionSourceOwner(requirements.slice(0, requirements.indexOf(block))) ||
          conditionalOwner(requirements.slice(0, requirements.indexOf(block)))) continue;
      const id = rule[2]!;
      const assessment = (value: string) => value.replace(/"[^"\n]*"|“[^”\n]*”/g,
        (quoted: string, index: number, source: string) =>
          /^(?:withdrawn|rejected|cancelled|canceled|optional|not current|no longer required)$/i.test(quoted.slice(1, -1)) &&
          new RegExp(`(?:^|[.!?]\\s+|\\n)[\\t ]*(?:Correction:\\s*)?(?:${id}(?: (?:verification|baseline verification|regression tests?))? (?:is|was|has been)|(?:this|the) (?:(?:unchanged-code|baseline) )?verification (?:is|was|has been)|(?:the|this) legacy golden (?:tests|suite) (?:are|is|were|was|have been|has been)) $`, 'i').test(source.slice(0, index))
            ? quoted.slice(1, -1) : '');
      const inactive = (value: string) => {
        const body = assessment(value).replace(/\b(?:these|the|this)\s+tests\s+(?:are|were|have been)\b/gi, 'this suite is')
          .replace(/\b(?:these|the|this)\s+tests\b/gi, 'this suite')
          .replace(/\b(?:this|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement');
        return withdrawn(body, id) || /\b(?:this|the|that) (?:requirement|suite|test) (?:is|was|has been) (?:not current|no longer current)\b/i.test(body) || new RegExp(`\\b${id}(?: (?:verification|baseline verification|regression tests?))? (?:is|was|has been) (?:withdrawn|rejected|cancelled|canceled|optional|not current|no longer required)\\b`, 'i').test(body);
      };
      if (inactive(block)) continue;
      const cancelled = new RegExp(`\\b${id}(?: (?:verification|baseline verification|regression tests?))? (?:is|was|has been) (?:withdrawn|rejected|cancelled|canceled|optional|not current|no longer required)\\b`, 'i');
      const changedFirst = new RegExp(`^(?:Correction:\\s*)?legacyAuthFlow(?:\\(\\))? (?:is|was|has been|will be) (?:modified|changed|rewritten|refactored) before ${id}\\b`, 'i');
      if (current.some(s => {
        const body = assessment(s.body.join('\n'));
        return cancelled.test(body) || /\b(?:the|this) legacy golden (?:tests|suite) (?:are|is|were|was|have been|has been) (?:withdrawn|rejected|cancelled|canceled|optional|not current|no longer required)\b/i.test(body) ||
          body.split(/\n|[.!?]\s+/).some(line => changedFirst.test(line.trim()));
      })) continue;
      const ordering = current.some(s => {
        if (s.title !== 'Implementation steps') return false;
        const body = unquoted(s.body.join('\n'));
        const step = new RegExp(`^[1-9]\\d*\\. Golden regression tests for legacyAuthFlow \\(${id}\\) [—–-] pin current outputs\\s+per input class before any other code moves\\. CRITICAL, lands first\\.`, 'm').exec(body);
        return Boolean(step && !extractionSourceOwner(body.slice(0, step.index)) && !conditionalOwner(body.slice(0, step.index)) &&
          !inactive(body) && snapshotSource.includes(step[0].replace(/\s+/g, ' ')));
      });
      if (!ordering) continue;
      for (const tasks of current.filter(s => s.title === 'Implementation Tasks')) {
        const body = tasks.body.join('\n').trim();
        for (const task of body.split(/\n(?=-\s)/)) {
          const match = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] ([A-Za-z][\w/.-]*\/legacyAuthFlow) tests [—–-] CRITICAL golden regression tests, land first[\t ]*(?:\n|$)/.exec(task);
          const file = /^\s+- Files: ([^\n]+)$/m.exec(task);
          const verify = /^\s+- Verify: (one|two|three|four|five|six|seven|eight|nine|ten|[1-9]\d*) input classes pinned; suite green against unmodified legacy code before any refactor commit[\t ]*$/m.exec(task);
          const prefix = unquoted(body.slice(0, body.indexOf(task))).trim().split('\n').at(-1) ?? '';
          if (!match || match[1] !== id || file?.[1] !== rule[1] || !verify ||
              !rule[1].startsWith(match[2] + '.regression.test.') ||
              !snapshotSource.includes(task.replace(/\s+/g, ' ').trim()) ||
              extractionSourceOwner(prefix) || conditionalOwner(prefix) ||
              extractionSourceOwner(unquoted(task.slice(0, verify.index))) || conditionalOwner(task.slice(0, verify.index)) || inactive(task)) continue;
          const count = /^\d+$/.test(verify[1]!) ? Number(verify[1]) : ['zero','one','two','three','four','five','six','seven','eight','nine','ten'].indexOf(verify[1]!);
          if (count === rule[3]!.split(',').length) return true;
        }
      }
    }
  }


  // A mandatory before-rewrite declaration binds exact captured behavior to
  // the same task file's current-code baseline and flag-on rerun.
  const approvalPending = (value: string) => unquoted(value).split('\n').some(line =>
    /^\s*(?:once|when|pending)\b[^.!?\n]{0,80}\bapprov(?:e[ds]?|al)\b/i.test(line));
  // A required fixture file can own the legacy oracle while its read-only
  // baseline task gates the scheduled task that changes the legacy module.
  for (const section of current.filter(s => /^CRITICAL: regression test for legacyAuthFlow\(\) \(regression rule, mandatory\)$/i.test(s.title))) {
    const body = unquoted(section.body.join(' ')).replace(/\s+/g, ' ').trim();
    const rule = /(?:^|\. )Before any rewrite: - ([A-Za-z][\w/.-]*\.test(?:\.[jt]s)?) records, for a fixture set of tenants and tokens, the exact claims returned and the exact error for each failure case \(([^()!?]{1,300})\)\. - The same fixture set is the shadow comparator's assertion set and stays as the permanent behavioral spec after legacy is deleted\./.exec(body);
    if (!rule || suiteWithdrawn || !snapshotSource.includes(rule[0].trim()) || withdrawn(body) ||
        extractionSourceOwner(body) || conditionalOwner(body) || approvalPending(body) ||
        !['expired', 'wrong audience', 'wrong issuer', 'suspended tenant', 'revoked token', 'malformed token'].every(kind => rule[2]!.split(',').map(item => item.trim()).includes(kind))) continue;
    for (const tasks of current.filter(s => s.title === 'Implementation Tasks')) {
      const taskBody = tasks.body.join('\n').trim(), blocks = taskBody.split(/\n(?=-\s)/), prefix = blocks[0]?.trim() ?? '';
      if (!taskBody.startsWith('- ') && (!/^Synthesized from (?:this|the) review's findings\./.test(prefix) ||
          extractionSourceOwner(prefix) || conditionalOwner(prefix) || approvalPending(prefix) || /(?:^|\n)\s*(?:assuming|provided)\b/i.test(unquoted(prefix)))) continue;
      const ids = blocks.map(block => /^- (?:\[[ xX]\] )?(T[1-9]\d*)\b/.exec(block)?.[1]).filter(Boolean);
      if (ids.length !== new Set(ids).size) continue;
      for (const task of blocks) {
        const match = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] [A-Za-z][\w/-]* [—–-] CRITICAL regression test capturing legacyAuthFlow\(\) behavior before any rewrite[\t ]*(?:\n|$)/.exec(task);
        const files = [...task.matchAll(/^\s+- Files: ([^\n]+)$/gm)];
        const verifies = [...task.matchAll(/^\s+- Verify: test passes against unmodified legacy; same fixtures drive shadow compare[\t ]*$/gm)];
        const verify = verifies[0], preceding = unquoted(taskBody.slice(0, taskBody.indexOf(task))).trim().split('\n').at(-1) ?? '';
        if (!match || files.length !== 1 || files[0]![1] !== rule[1] || verifies.length !== 1 ||
            (task.match(/^\s+- Verify:/gm)?.length ?? 0) !== 1 || !snapshotSource.includes(task.replace(/\s+/g, ' ').trim()) ||
            extractionSourceOwner(preceding) || conditionalOwner(preceding) || approvalPending(preceding) ||
            extractionSourceOwner(task.slice(0, verify!.index)) || conditionalOwner(task.slice(0, verify!.index)) || approvalPending(task.slice(0, verify!.index)) ||
            /(?:^|\n)\s*(?:assuming|provided)\b/i.test(unquoted(task.slice(0, verify!.index)))) continue;
        const id = match[1]!, status = '(?:withdrawn|rejected|declined|cancelled|canceled|superseded|deferred|optional|not current|no longer current|not required|no longer required)';
        const assessment = (value: string) => unquoted(value.replace(new RegExp(
          `((?:^|[.!?;]\\s+|\\n)[\\t ]*(?:Correction:\\s*)?(?:${id}(?: (?:baseline requirement|verification|baseline verification))?|(?:this|the) (?:(?:legacy|baseline|unchanged-code) )?(?:(?:regression|characterization) )?(?:suite|requirement|verification)) (?:is|was|has been) )["“'‘](${status})["”'’]`, 'gim'), '$1$2'))
          .replace(/(?<![A-Za-z0-9])'[^'\n]*'(?![A-Za-z0-9])|‘[^’\n]*’/g, '')
          .split(/\n|[.!?]\s+/).filter(line => !conditionalOwner(line) && !approvalPending(line) && !/^\s*(?:assuming|provided)\b/i.test(line)).join('\n');
        const cancelled = new RegExp(`\\b${id}(?: (?:baseline requirement|verification|baseline verification))? (?:is|was|has been) ${status}\\b`, 'i');
        const inactive = (value: string) => {
          const owned = assessment(value).replace(/\b(?:this|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement');
          return withdrawn(owned, id) || cancelled.test(owned) || new RegExp(`\\b(?:this|the) (?:suite|requirement) (?:is|was|has been) ${status}\\b`, 'i').test(owned);
        };
        const statusRow = new RegExp(`^\\s*\\|\\s*${id}\\s*\\|\\s*["“'‘]?${status}["”'’]?\\s*\\|`, 'im');
        const changedFirst = new RegExp(`^(?:Correction:\\s*)?legacyAuthFlow\\(\\) (?:is|was|has been|will be) (?:modified|changed|rewritten|refactored) before ${id}\\b`, 'im');
        if (inactive(body) || inactive(task) || current.some(s => {
          const value = assessment(s.body.join('\n'));
          return statusRow.test(s.body.join('\n')) || cancelled.test(value) || changedFirst.test(value) ||
            new RegExp(`\\b(?:the|this) legacy (?:regression|characterization) (?:suite|tests?|requirement) (?:is|was|has been) ${status}\\b`, 'i').test(value);
        })) continue;
        for (const strategy of current.filter(s => s.title === 'Worktree parallelization strategy')) {
          const schedule = unquoted(strategy.body.join('\n'));
          const rows = [...schedule.matchAll(/^\| (T[1-9]\d*) ([^|]+) \| ([^|]+) \| ([^|]+) \|$/gm)];
          if (rows.length !== new Set(rows.map(row => row[1])).size || extractionSourceOwner(schedule) || approvalPending(schedule) || inactive(schedule) ||
              schedule.split('\n').some(line => conditionalOwner(line) || /^\s*(?:assuming|provided)\b/i.test(line))) continue;
          const baseline = rows.find(row => row[1] === id && row[2] === 'legacy regression test' && row[4] === '—');
          const modules = baseline && /^([A-Za-z][\w/-]*) \(read\), ([A-Za-z][\w/-]*)$/.exec(baseline[3]!);
          const writers = modules ? rows.filter(row => row[1] !== id && row[3]!.split(',').map(item => item.trim()).includes(modules[1]!)) : [];
          if (modules && rule[1]!.startsWith(modules[2] + '/') && writers.length > 0 &&
              writers.every(row => row[4]!.split(',').map(item => item.trim()).includes(id)) &&
              snapshotSource.includes(baseline![0].replace(/\s+/g, ' ').trim())) return true;
        }
      }
    }
  }
  for (const section of current.filter(s => s.title === 'REGRESSION RULE (mandatory, no decision required)')) {
    const body = unquoted(section.body.join(' ')).replace(/\s+/g, ' ').trim();
    const rule = /^legacyAuthFlow\(\) is existing behavior being rewritten\b[^!?]{1,240}\. CRITICAL: before any rewrite, record a characterization suite in ([A-Za-z][\w/.-]*\.test\.[jt]s): for each supported tenant configuration, capture inputs \([^()!?]{1,300}\) and the exact output \([^()!?]{1,300}\)\. The new path must pass the same suite with the flag on\. This is the parity gate for D[1-9]\d*\.$/.exec(body);
    if (!rule || suiteWithdrawn || !snapshotSource.includes(body) || withdrawn(body) ||
        /\b(?:if|unless|maybe|might|could|optional|hypothetical|unproven)\b/i.test(body)) continue;
    for (const tasks of current.filter(s => s.title === 'Implementation Tasks')) {
      const taskBody = tasks.body.join('\n').trim(), blocks = taskBody.split(/\n(?=-\s)/);
      const prefix = blocks[0]?.trim() ?? '';
      if (!taskBody.startsWith('- ') && (!/^Synthesized from (?:this|the) review's findings\./.test(prefix) ||
          extractionSourceOwner(prefix) || approvalPending(prefix) || /\b(?:if|unless|assuming|provided|optional|hypothetical|unproven)\b/i.test(unquoted(prefix)))) continue;
      const ids = blocks.map(block => /^- (?:\[[ xX]\] )?(T[1-9]\d*)\b/.exec(block)?.[1]).filter(Boolean);
      if (ids.length !== new Set(ids).size) continue;
      for (const task of blocks) {
        const match = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] [A-Za-z][\w/-]* [—–-] Write the legacyAuthFlow\(\) characterization \(regression\) suite before any rewrite[\t ]*(?:\n|$)/.exec(task);
        const file = /^\s+- Files: ([^\n]+)$/m.exec(task);
        const verify = /^\s+- Verify: suite green on current code; green again with flag on after rewrite[\t ]*$/m.exec(task);
        const preceding = unquoted(taskBody.slice(0, taskBody.indexOf(task))).trim().split('\n').at(-1) ?? '';
        if (!match || file?.[1] !== rule[1] || !verify || !snapshotSource.includes(task.replace(/\s+/g, ' ').trim()) ||
            extractionSourceOwner(preceding) || conditionalOwner(preceding) || approvalPending(preceding) ||
            extractionSourceOwner(task.slice(0, verify.index)) || conditionalOwner(task.slice(0, verify.index)) || approvalPending(task.slice(0, verify.index)) ||
            /(?:^|\n)\s*(?:assuming|provided)\b/i.test(unquoted(task.slice(0, verify.index)))) continue;
        const id = match[1]!;
        // Preserve a quoted status word on a current subject, while still
        // ignoring quoted historical sentences and foreign suite withdrawals.
        const assessment = (value: string) => unquoted(value.replace(new RegExp(
          `(\\b(?:${id}(?: (?:verification|baseline verification|rerun))?|(?:this|the) (?:(?:legacy|baseline|unchanged-code) )?(?:(?:regression|characterization) )?(?:suite|requirement|verification)) (?:is|was|has been) )["“](withdrawn|rejected|cancelled|canceled|superseded|optional|not current|no longer required)["”]`, 'gi'), '$1$2'));
        const inactive = (value: string) => {
          const body = assessment(value).replace(/\b(?:this|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement');
          return withdrawn(body, id) || /\b(?:this|the) (?:suite|requirement) (?:is|was|has been) (?:superseded|not current|no longer current)\b/i.test(body);
        };
        const cancelled = new RegExp(`\\b${id}(?: (?:verification|baseline verification|rerun))? (?:is|was|has been) (?:withdrawn|rejected|cancelled|canceled|superseded|optional|not current|no longer required)\\b`, 'i');
        const changedFirst = new RegExp(`^(?:Correction:\\s*)?legacyAuthFlow\\(\\) (?:is|was|has been|will be) (?:modified|changed|rewritten|refactored) before ${id}\\b`, 'i');
        const statusRow = new RegExp(`^\\s*\\|\\s*${id}\\s*\\|\\s*["“]?(?:withdrawn|rejected|cancelled|canceled|superseded|optional|not current|no longer required)["”]?\\s*\\|`, 'im');
        if (inactive(task) || current.some(s => {
          const value = assessment(s.body.join('\n'));
          return statusRow.test(s.body.join('\n')) || cancelled.test(value) || /\b(?:the|this) legacy (?:regression|characterization) (?:suite|tests?|requirement) (?:is|was|has been) (?:withdrawn|rejected|cancelled|canceled|superseded|optional|not current|no longer required)\b/i.test(value) ||
            value.split(/\n|[.!?]\s+/).some(line => changedFirst.test(line.trim()));
        })) continue;
        return true;
      }
    }
  }

  // A mandatory current-output baseline can land before all other tasks.
  // This obligation does not imply an identical suite on the flag-on path:
  // a plan may specify its rollout parity check separately.
  for (const section of current.filter(s => /^CRITICAL [—–-] regression \(mandatory, REGRESSION RULE\)$/i.test(s.title))) {
    const body = unquoted(section.body.join(' ')).replace(/\s+/g, ' ').trim();
    const rule = /^legacyAuthFlow\(\) is (?:live|existing|current) behavior being (?:changed|modified|refactored) with no covering test(?: \([^()!?]{1,120}\))?\. Before any (?:rewrite|refactor|change): ([A-Za-z][\w/.-]*\.test\.[jt]s) (?:records|captures|pins) (?:current|existing) outputs \(including quirks\) for [^.!?]{1,300} inputs\. This suite runs against the legacy path now\b/.exec(body);
    if (!rule || suiteWithdrawn || !snapshotSource.includes(rule[0]) || withdrawn(body) ||
        extractionSourceOwner(body) || approvalPending(body) || /\b(?:if|unless|maybe|might|could|optional|hypothetical|unproven)\b/i.test(body)) continue;
    for (const tasks of current.filter(s => s.title === 'Implementation Tasks')) {
      const taskBody = tasks.body.join('\n').trim(), blocks = taskBody.split(/\n(?=-\s)/);
      const prefix = blocks[0]?.trim() ?? '';
      if (!taskBody.startsWith('- ') && (!/^Synthesized from (?:this|the) review's findings\./.test(prefix) ||
          extractionSourceOwner(prefix) || approvalPending(prefix) || /\b(?:if|unless|assuming|provided|optional|hypothetical|unproven)\b/i.test(unquoted(prefix)))) continue;
      const ids = blocks.map(block => /^- (?:\[[ xX]\] )?(T[1-9]\d*)\b/.exec(block)?.[1]).filter(Boolean);
      if (ids.length !== new Set(ids).size) continue;
      for (const task of blocks) {
        const match = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] [A-Za-z][\w/-]* [—–-] CRITICAL regression: characterization suite for legacyAuthFlow\(\) (?:current|existing|prior) behavior[\t ]*(?:\n|$)/.exec(task);
        const files = [...task.matchAll(/^\s+- Files: ([^\n]+)$/gm)];
        const verifies = [...task.matchAll(/^\s+- Verify: ([^\n]+)$/gm)];
        const verify = verifies[0];
        const preceding = unquoted(taskBody.slice(0, taskBody.indexOf(task))).trim().split('\n').at(-1) ?? '';
        if (!match || files.length !== 1 || files[0]![1] !== rule[1] || verifies.length !== 1 ||
            !/^suite green against unmodified legacy before any other task merges[\t ]*$/.test(verify![1]!) ||
            !snapshotSource.includes(task.replace(/\s+/g, ' ').trim()) ||
            extractionSourceOwner(preceding) || conditionalOwner(preceding) || approvalPending(preceding) ||
            extractionSourceOwner(task.slice(0, verify!.index)) || conditionalOwner(task.slice(0, verify!.index)) || approvalPending(task.slice(0, verify!.index)) ||
            /(?:^|\n)\s*(?:assuming|provided)\b/i.test(unquoted(task.slice(0, verify!.index)))) continue;
        const id = match[1]!;
        const status = '(?:withdrawn|rejected|cancelled|canceled|superseded|optional|not current|no longer current|not required|no longer required)';
        // Current scalar statuses retain their owner; whole-sentence quoted
        // history and conditional future statuses cannot cancel this baseline.
        const assessment = (value: string) => unquoted(value.replace(new RegExp(
          `((?:^|[.!?]\\s+|\\n)[\\t ]*(?:Correction:\\s*)?(?:${id}(?: (?:verification|baseline verification))?|(?:this|the) (?:(?:legacy|baseline|unchanged-code) )?(?:(?:regression|characterization) )?(?:suite|requirement|verification)) (?:is|was|has been) )["“'‘](${status})["”'’]`, 'gim'), '$1$2'))
          .split(/\n|[.!?]\s+/).filter(line => !conditionalOwner(line) && !approvalPending(line) && !/^\s*(?:assuming|provided)\b/i.test(line)).join('\n');
        const inactive = (value: string) => {
          const body = assessment(value).replace(/\b(?:this|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement');
          return withdrawn(body, id) || new RegExp(`\\b(?:this|the) (?:suite|requirement) (?:is|was|has been) ${status}\\b`, 'i').test(body);
        };
        const cancelled = new RegExp(`\\b${id}(?: (?:verification|baseline verification))? (?:is|was|has been) ${status}\\b`, 'i');
        const statusRow = new RegExp(`^\\s*\\|\\s*${id}\\s*\\|\\s*["“'‘]?${status}["”'’]?\\s*\\|`, 'im');
        const changedFirst = new RegExp(`^(?:Correction:\\s*)?legacyAuthFlow\\(\\) (?:is|was|has been|will be) (?:modified|changed|rewritten|refactored) before ${id}\\b`, 'im');
        if (inactive(body) || inactive(task) || current.some(s => {
          const value = assessment(s.body.join('\n'));
          return statusRow.test(s.body.join('\n')) || cancelled.test(value) || changedFirst.test(value) ||
            new RegExp(`\\b(?:the|this) legacy (?:regression|characterization) (?:suite|tests?|requirement) (?:is|was|has been) ${status}\\b`, 'i').test(value);
        })) continue;
        return true;
      }
    }
  }

  // A directory-owned characterization task can name changed worktree steps
  // in its baseline check, with the baseline's own lane merging first.
  for (const section of current.filter(s => /^Tests(?: \([^\n)]+\))?$/.test(s.title))) {
    const body = unquoted(section.body.join(' ')).replace(/\s+/g, ' ').trim();
    const rule = /^CRITICAL regression suite \(mandatory, IRON RULE\)\. legacyAuthFlow\(\) is existing behavior being rewritten and the original plan had no regression coverage\. Before any rewrite, write a characterization suite that pins current behavior: [^.!?]{1,300}\. The suite runs against both the legacy path and the new flow \(via the flag\) for the whole rollout window\./.exec(body);
    if (!rule || suiteWithdrawn || !snapshotSource.includes(rule[0]) || withdrawn(body) ||
        /\b(?:if|unless|maybe|might|could|optional|hypothetical|unproven)\b/i.test(rule[0])) continue;
    for (const tasks of current.filter(s => s.title === 'Implementation Tasks')) {
      const taskBody = tasks.body.join('\n').trim(), blocks = taskBody.split(/\n(?=-\s)/), prefix = blocks[0]?.trim() ?? '';
      if (!taskBody.startsWith('- ') && (!/^Synthesized from (?:this|the) review's findings\./.test(prefix) || extractionSourceOwner(prefix) ||
          approvalPending(prefix) || /\b(?:if|unless|assuming|provided|optional|hypothetical|unproven)\b/i.test(unquoted(prefix)))) continue;
      const ids = blocks.map(block => /^- (?:\[[ xX]\] )?(T[1-9]\d*)\b/.exec(block)?.[1]).filter(Boolean);
      if (ids.length !== new Set(ids).size) continue;
      for (const task of blocks) {
        const match = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] ([A-Za-z][\w/-]*) [—–-] Write the CRITICAL characterization suite for legacyAuthFlow\(\) before any rewrite; run it against legacy and new flow[\t ]*(?:\n|$)/.exec(task);
        const files = [...task.matchAll(/^\s+- Files: ([^\n]+)$/gm)];
        const verifies = [...task.matchAll(/^\s+- Verify: suite green on legacy path before (S[1-9]\d*)\/(S[1-9]\d*) land; green on both paths after[\t ]*$/gm)];
        const verify = verifies[0], preceding = unquoted(taskBody.slice(0, taskBody.indexOf(task))).trim().split('\n').at(-1) ?? '';
        if (!match || files.length !== 1 || files[0]![1] !== `${match[2]}/, router flag stub` || verifies.length !== 1 ||
            (task.match(/^\s+- Verify:/gm)?.length ?? 0) !== 1 || !snapshotSource.includes(task.replace(/\s+/g, ' ').trim()) ||
            extractionSourceOwner(preceding) || conditionalOwner(preceding) || approvalPending(preceding) ||
            extractionSourceOwner(task.slice(0, verify!.index)) || conditionalOwner(task.slice(0, verify!.index)) || approvalPending(task.slice(0, verify!.index)) ||
            /(?:^|\n)\s*(?:assuming|provided)\b/i.test(unquoted(task.slice(0, verify!.index)))) continue;
        for (const strategy of current.filter(s => s.title === 'Worktree parallelization strategy')) {
          const schedule = unquoted(strategy.body.join('\n'));
          const steps = [...schedule.matchAll(/^\| (S[1-9]\d*)\b/gm)].map(row => row[1]);
          if (steps.length !== new Set(steps).size) continue;
          const baseline = /^\| (S[1-9]\d*) Regression suite for legacyAuthFlow\(\) \| ([A-Za-z][\w/-]*) \| [—–-] \|$/m.exec(schedule);
          const lanes = baseline ? [...schedule.matchAll(new RegExp(`^\\s*Lane ([A-Z]): ${baseline[1]} \\(independent\\)$`, 'gm'))] : [];
          const lane = lanes.length === 1 ? lanes[0] : undefined;
          const order = lane && new RegExp(`^Execution order: launch [A-Z](?:, [A-Z])+ in parallel worktrees\\. Merge ${lane[1]} first \\(it is\\s+pure tests and gates the rewrite\\)\\.`, 'm').exec(schedule);
          if (!baseline || baseline[2] !== match[2] || !lane || !order || verify![1] === verify![2] ||
              !new RegExp(`^\\| ${verify![1]} AuthBroker \\+ SessionMint \\| [^|]+ \\| [^|]+ \\|$`, 'm').test(schedule) ||
              !new RegExp(`^\\| ${verify![2]} Flattened dispatcher \\+ flag router \\+ fallback \\| [^|]+ \\| [^|]+ \\|$`, 'm').test(schedule) ||
              extractionSourceOwner(schedule.slice(0, order.index)) || conditionalOwner(schedule.slice(0, order.index)) || approvalPending(schedule.slice(0, order.index)) ||
              !snapshotSource.includes(order[0].replace(/\s+/g, ' '))) continue;
          const id = `(?:${match[1]}|${baseline[1]})`, status = '(?:withdrawn|rejected|cancelled|canceled|superseded|optional|not current|no longer current|not required|no longer required)';
          const assessment = (value: string) => unquoted(value.replace(new RegExp(
            `((?:^|[.!?]\\s+|\\n)[\\t ]*(?:Correction:\\s*)?(?:${id}(?: (?:verification|baseline verification))?|(?:this|the) (?:(?:legacy|baseline|unchanged-code) )?(?:(?:regression|characterization) )?(?:suite|requirement|verification)) (?:is|was|has been) )["“'‘](${status})["”'’]`, 'gim'), '$1$2'))
            .replace(/(?<![A-Za-z0-9])'[^'\n]*'(?![A-Za-z0-9])|‘[^’\n]*’/g, '')
            .split(/\n|[.!?]\s+/).filter(line => !conditionalOwner(line) && !approvalPending(line) && !/^\s*(?:assuming|provided)\b/i.test(line)).join('\n');
          const inactive = (value: string) => {
            const text = assessment(value).replace(/\b(?:this|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement');
            return withdrawn(text, id) || new RegExp(`\\b(?:this|the) (?:suite|requirement) (?:is|was|has been) ${status}\\b`, 'i').test(text);
          };
          const cancelled = new RegExp(`\\b${id}(?: (?:verification|baseline verification))? (?:is|was|has been) ${status}\\b`, 'i');
          const statusRow = new RegExp(`^\\s*\\|\\s*${id}\\s*\\|\\s*["“'‘]?${status}["”'’]?\\s*\\|`, 'im');
          const changedFirst = new RegExp(`^(?:Correction:\\s*)?legacyAuthFlow\\(\\) (?:is|was|has been|will be) (?:modified|changed|rewritten|refactored) before ${id}\\b`, 'im');
          if (inactive(body) || inactive(task) || current.some(s => {
            const value = assessment(s.body.join('\n'));
            return statusRow.test(s.body.join('\n')) || cancelled.test(value) || changedFirst.test(value) ||
              new RegExp(`\\b(?:the|this) (?:legacy (?:regression|characterization) (?:suite|tests?|requirement)|(?:baseline|unchanged-code) verification) (?:is|was|has been) ${status}\\b`, 'i').test(value);
          })) continue;
          return true;
        }
      }
    }
  }

  // A blocking declaration can bind its task to the first ordered step:
  // characterize both existing entry points before any implementation changes.
  for (const section of current.filter(s => /^REGRESSION \(CRITICAL, mandatory under the regression rule, no question asked\)$/i.test(s.title))) {
    const body = unquoted(section.body.join(' ')).replace(/\s+/g, ' ').trim();
    const rule = /(?:^|\. )(T[1-9]\d*) is a blocking requirement: before any rewrite, (?:capture|record|pin) the current behavior of legacyAuthFlow\(\) and validateAndDispatch\(\) as a characterization suite: every accepted token shape, every rejected token shape, every error response, for at least (?:two|[2-9]\d*) tenants\. The same suite runs against the AuthBroker path behind the flag and must produce identical outcomes\b/.exec(body);
    if (!rule || suiteWithdrawn || !snapshotSource.includes(rule[0].trim()) ||
        extractionSourceOwner(body) || conditionalOwner(body) || approvalPending(body)) continue;
    const id = rule[1]!;
    const status = '(?:withdrawn|rejected|declined|cancelled|canceled|superseded|deferred|optional|not current|no longer current|not required|no longer required)';
    const taskSubject = `${id}(?: (?:baseline requirement|verification|baseline verification|regression tests?))?`;
    const assessment = (value: string) => unquoted(value.replace(new RegExp(
      `((?:^|[.!?]\\s+|\\n)[\\t ]*(?:Correction:\\s*)?(?:${taskSubject}|(?:this|the) (?:(?:legacy|baseline|unchanged-code) )?(?:(?:regression|characterization) )?(?:suite|requirement|verification)) (?:is|was|has been) )["“'‘](${status})["”'’]`, 'gim'), '$1$2'))
      .split(/\n|[.!?]\s+/).filter(line => !conditionalOwner(line) && !approvalPending(line) && !/^\s*(?:assuming|provided)\b/i.test(line)).join('\n');
    const cancelled = new RegExp(`\\b${taskSubject} (?:is|was|has been) ${status}\\b`, 'i');
    const inactive = (value: string) => {
      const owned = assessment(value).replace(/\b(?:this|the)\s+(?:(?:unchanged-code|baseline)\s+)?verification\b/gi, 'this requirement');
      return withdrawn(owned, id) || cancelled.test(owned) ||
        new RegExp(`\\b(?:this|the) (?:suite|requirement) (?:is|was|has been) ${status}\\b`, 'i').test(owned);
    };
    const statusRow = new RegExp(`^\\s*\\|\\s*${id}\\s*\\|\\s*["“'‘]?${status}["”'’]?\\s*\\|`, 'im');
    const changedFirst = new RegExp(`^(?:Correction:\\s*)?legacyAuthFlow\\(\\) (?:is|was|has been|will be) (?:modified|changed|rewritten|refactored) before ${id}\\b`, 'im');
    if (inactive(body) || current.some(s => {
      const value = assessment(s.body.join('\n'));
      return statusRow.test(s.body.join('\n')) || cancelled.test(value) || changedFirst.test(value) ||
        new RegExp(`\\b(?:the|this) legacy (?:regression|characterization) (?:suite|tests?|requirement) (?:is|was|has been) ${status}\\b`, 'i').test(value);
    })) continue;
    const baseline = current.some(s => {
      if (s.title !== 'Implementation steps (ordered)') return false;
      const schedule = unquoted(s.body.join('\n')).trim();
      const first = new RegExp(`^1\\. ${id} Characterization suite for legacyAuthFlow\\(\\) and validateAndDispatch\\(\\)\\. Green on current code before anything else changes\\.[\\t ]*(?:\\n|$)`).exec(schedule);
      return Boolean(first && !inactive(schedule) && snapshotSource.includes(first[0].replace(/\s+/g, ' ').trim()));
    });
    if (!baseline) continue;
    for (const tasks of current.filter(s => s.title === 'Implementation Tasks')) {
      const taskBody = tasks.body.join('\n').trim(), blocks = taskBody.split(/\n(?=-\s)/), prefix = blocks[0]?.trim() ?? '';
      if (!taskBody.startsWith('- ') && (!/^Synthesized from (?:this|the) review's findings\./.test(prefix) ||
          extractionSourceOwner(prefix) || conditionalOwner(prefix) || approvalPending(prefix) ||
          /(?:^|\n)\s*(?:assuming|provided)\b/i.test(unquoted(prefix)))) continue;
      const ids = blocks.map(block => /^- (?:\[[ xX]\] )?(T[1-9]\d*)\b/.exec(block)?.[1]).filter(Boolean);
      if (ids.length !== new Set(ids).size) continue;
      for (const task of blocks) {
        const match = /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] [A-Za-z][\w/-]* [—–-] Write the characterization\/regression suite for legacyAuthFlow\(\) and validateAndDispatch\(\) before any rewrite \(CRITICAL\)[\t ]*(?:\n|$)/.exec(task);
        const files = [...task.matchAll(/^\s+- Files: [^,\n]+, (?:tests?|__tests__)\/[A-Za-z][\w/.-]*[\t ]*$/gm)];
        const verifies = [...task.matchAll(/^\s+- Verify: suite green on current code; later green on both flag states[\t ]*$/gm)];
        const verify = verifies[0], preceding = unquoted(taskBody.slice(0, taskBody.indexOf(task))).trim().split('\n').at(-1) ?? '';
        if (!match || match[1] !== id || files.length !== 1 || verifies.length !== 1 ||
            (task.match(/^\s+- Verify:/gm)?.length ?? 0) !== 1 || !snapshotSource.includes(task.replace(/\s+/g, ' ').trim()) ||
            extractionSourceOwner(preceding) || conditionalOwner(preceding) || approvalPending(preceding) ||
            extractionSourceOwner(task.slice(0, verify!.index)) || conditionalOwner(task.slice(0, verify!.index)) || approvalPending(task.slice(0, verify!.index)) ||
            /(?:^|\n)\s*(?:assuming|provided)\b/i.test(unquoted(task.slice(0, verify!.index))) || inactive(task)) continue;
        return true;
      }
    }
  }

  // A required-test item may own the named legacy oracle while a separate
  // parity item and task preserve its compatibility obligation. Bind these
  // small obligations structurally; unrelated prose cannot complete the chain.
  for (const section of current.filter(s => /^Required tests(?: \([^\n]*\))?$/i.test(s.title))) {
    const blocks = section.body.join('\n').trim().split(/\n\s*\n/);
    for (const block of blocks) {
      const claim = block.replace(/\s+/g, ' ').trim();
      const rule = /^CRITICAL\s*\([^)]*\bmandatory\b[^)]*\):\s*([A-Za-z][\w/.-]*\.test\.[jt]s)\./i.exec(claim);
      if (!rule || /\b(?:not|never|no longer)\s+mandatory\b/i.test(rule[0]) || !/^\s*(?:Pin|Capture|Record) current behavior of legacyAuthFlow\(\) before any (?:change|rewrite|refactor):/i.test(claim.slice(rule[0].length))
          || !/\bThis is the oracle for the parity suite\b/i.test(claim) || !snapshotSource.includes(claim)) continue;
      const quoteFree = (value: string) => value.replace(/"[^"\n]*"|“[^”\n]*”|(?<![\w])'[^'\n]*'(?![\w])|‘[^’\n]*’/g, '');
      const inactiveWords = '(?:withdrawn|rejected|declined|cancelled|canceled|superseded|deferred|optional|proposed|not current|no longer current|not required|no longer required|hypothetical|unproven)';
      const subject = '(?:(?:this|the) (?:(?:legacy|baseline|unchanged-code) )?(?:(?:regression|characterization|parity) )?(?:suite|tests?|requirement|verification|oracle))';
      const currentText = (value: string, ids: string) => quoteFree(value.replace(new RegExp(
        `((?:^|[.!?;]\\s+|\\n)[\\t ]*(?:Correction:\\s*)?(?:${ids}|${subject}) (?:is|are|was|were|has been|have been) )["“'‘](${inactiveWords})["”'’]`, 'gim'), '$1$2'));
      // Input conditions describe asserted behavior, including accepted tokens.
      // An implicit approval or an explicit work/approver subject instead
      // governs whether this work exists.
      const conditionalApproval = /(?:^|[.!?;]\s+|\n)[\t ]*(?:if|unless|assuming|provided|once|when|pending|after)\s+(?:(?:approv\w*|authoriz\w*|consent|confirm\w*|accept\w*|desired|requested|needed)\b|(?:(?:this|the|our) )?(?:work|plan|review|task|baseline|parity|regression|characterization|suite|tests?|requirement|verification|proposal|implementation|T[1-9]\d*|we|you|they|reviewer|owner|user)\b[^.!?;,\n]{0,80}\b(?:approv\w*|authoriz\w*|consent|confirm\w*|accept\w*|desired|requested|needed|proceed)\b)/i;
      const unowned = (value: string) => extractionSourceOwner(value) || /\b(?:proposed|optional|hypothetical|unproven|maybe|might|could)\b/i.test(quoteFree(value)) || conditionalApproval.test(quoteFree(value));
      const inactive = (value: string, ids: string) => unowned(value) || new RegExp(
        `\\b(?:${ids}|${subject}) (?:is|are|was|were|has been|have been) ${inactiveWords}\\b|\\b(?:skip|defer|omit) (?:the |this )?(?:baseline|regression|characterization|parity) (?:test|suite|verification)`, 'i').test(currentText(value, ids));
      if (inactive(block, 'T[1-9]\\d*')) continue;
      for (const parityBlock of blocks) {
        const parity = parityBlock.replace(/\s+/g, ' ').trim();
        const comparison = /^Decision [1-9]\d*[A-D], parity suite:\s*([A-Za-z][\w/.-]*\.test\.[jt]s)\./i.exec(parity);
        if (!comparison || inactive(parityBlock, 'T[1-9]\\d*') || !snapshotSource.includes(parity)
            || !/^\s*(?:One|The same) fixture table, each row run through both paths \(flag off, flag on\), assert identical outcomes?\b/i.test(parity.slice(comparison[0].length))) continue;
        for (const tasks of current.filter(s => s.title === 'Implementation Tasks')) {
          const taskBody = tasks.body.join('\n').trim(), taskBlocks = taskBody.split(/\n(?=-\s)/);
          const rows = taskBlocks.map(body => ({ body, match: /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–-] ([^\n]+)(?:\n|$)/.exec(body) })).filter(row => row.match);
          if (rows.length !== new Set(rows.map(row => row.match![1])).size) continue;
          const field = (body: string, name: string) => {
            const found = [...body.matchAll(new RegExp(`^  - ${name}: ([^\\n]+)$`, 'gm'))];
            return found.length === 1 ? found[0]![1] : undefined;
          };
          // Match the asserted action after its component label. A later
          // positive test phrase cannot override a leading "Do not write".
          const taskAction = (title: string) => /^[^\n]*?\s+[—–-]\s+(.+)$/.exec(title)?.[1] ?? title;
          const ownedTask = (body: string) => {
            // Source quotations identify the finding but cannot grant or revoke
            // its separately asserted action or verification.
            const action = body.replace(/^  - Surfaced by:.*$/gm, '');
            const preceding = taskBody.slice(0, taskBody.indexOf(body)).trim().split('\n').at(-1) ?? '';
            return !unowned(action) && !unowned(preceding) && snapshotSource.includes(body.replace(/\s+/g, ' ').trim());
          };
          for (const baseline of rows) {
            const title = baseline.match![2]!, id = baseline.match![1]!;
            if (!/^(?:(?:Write|Add|Create) (?:the )?)?CRITICAL (?:regression|characterization) tests? (?:pinning|capturing|recording) current legacyAuthFlow\(\) behavior before any (?:change|rewrite|refactor)\b/i.test(taskAction(title))
                || field(baseline.body, 'Files') !== rule[1] || !ownedTask(baseline.body)
                || !/^(?:test|suite) passes against (?:unmodified|unchanged|untouched) legacyAuthFlow\(\) (?:first|before any (?:change|rewrite|refactor))$/i.test(field(baseline.body, 'Verify') ?? '')) continue;
            for (const next of rows) {
              const nextId = next.match![1]!;
              if (nextId === id || field(next.body, 'Files') !== comparison[1] || !ownedTask(next.body)
                  || !/^(?:(?:Write|Add|Implement) (?:the )?)?(?:Table-driven )?parity suite running each fixture row through flag-off and flag-on paths\b/i.test(taskAction(next.match![2]!))
                  || !/^suite green for every row\b/i.test(field(next.body, 'Verify') ?? '')) continue;
              const ids = `(?:${id}|${nextId})(?: (?:baseline requirement|baseline verification|verification|rerun))?`;
              if ([block, parityBlock, baseline.body, next.body].some(value => inactive(value.replace(/^  - Surfaced by:.*$/gm, ''), ids))) continue;
              const cancelled = new RegExp(`\\b${ids} (?:is|was|has been) ${inactiveWords}\\b`, 'i');
              const changedFirst = new RegExp(`^(?:Correction:\\s*)?legacyAuthFlow\\(\\) (?:is|was|has been|will be) (?:modified|changed|rewritten|refactored) before ${id}\\b`, 'i');
              const withdrawn = current.some(s => {
                if (/\b(?:history|historical|source|quoted|example)\b/i.test(s.title)) return false;
                const body = s.body.join('\n');
                if (new RegExp(`^\\s*\\|\\s*(?:${id}|${nextId})\\s*\\|\\s*["“'‘]?${inactiveWords}["”'’]?\\s*\\|`, 'im').test(body)) return true;
                return currentText(body, ids).split(/\n|[.!?;]\s+/).some(line => !extractionSourceOwner(line) && !/\b(?:if|unless|assuming|provided)\b|\b(?:once|when|pending|after)\b[^.!?\n]{0,50}\bapprov/i.test(line) && (cancelled.test(line) || changedFirst.test(line.trim())
                  || new RegExp(`\\b(?:the|this) legacy (?:regression|characterization) (?:suite|tests?|requirement) (?:is|are|was|were|has been|have been) ${inactiveWords}\\b`, 'i').test(line)));
              });
              if (!withdrawn) return true;
            }
          }
        }
      }
    }
  }

  // A bold inline regression rule may bind two test files through a table
  // and one task: the recorded legacy baseline and its same-fixture parity.
  for (const section of current.filter(s => s.title === 'Tests')) {
    const body = section.body.join('\n');
    const paragraphs = body.split(/\n\s*\n/).map(p => p.replace(/\s+/g, ' ').trim());
    const rule = paragraphs.map(p => /^REGRESSION RULE \(mandatory, no decision required\): legacyAuthFlow\(\) is existing behavior being modified with no covering test(?: \([^()!?]{1,120}\))?\. A regression test is a CRITICAL requirement of this plan: (?:record|capture|pin) legacyAuthFlow\(\) outputs on a fixture set covering [^.!?]{1,300}, before any rewrite begins\. A parity test then runs the same fixtures through ([A-Za-z][\w]*) and asserts identical results\. Both live until the legacy path is deleted\.$/.exec(p)).find(Boolean);
    if (!rule || suiteWithdrawn || !snapshotSource.includes(rule[0])) continue;
    const conditional = /(?:^|[.!?;]\s+|\n)\s*(?:if|unless|once|when|assuming|provided|pending)\s+(?:(?:approv\w*|authoriz\w*|accept\w*|requested)\b|(?:this work|the requirement|we|you|the reviewer)\b[^.!?;\n]{0,80}\b(?:approv\w*|authoriz\w*|accept\w*)\b)/i;
    const status = '(?:withdrawn|rejected|cancelled|canceled|superseded|deferred|optional|proposed|not current|no longer current|not required|no longer required)';
    const assessment = (value: string, id: string) => unquoted(value.replace(new RegExp(
      `((?:^|[.!?;]\\s+|\\n)\\s*(?:Correction:\\s*)?(?:${id}(?: baseline verification)?|(?:this|the) (?:(?:legacy|baseline) )?(?:(?:regression|parity) )?(?:suite|test|requirement|verification)) (?:is|was|has been) )["“'‘](${status})["”'’]`, 'gim'), '$1$2'))
      .replace(/(?<!\w)'[^'\n]*'(?!\w)|‘[^’\n]*’/g, '');
    const inactive = (value: string, id: string, global = false) => {
      const text = assessment(value, id);
      const subject = global ? `${id}(?: baseline verification)?|(?:this|the) legacy (?:regression|parity) (?:suite|test|requirement)`
        : `${id}(?: baseline verification)?|(?:this|the) (?:(?:legacy|baseline) )?(?:(?:regression|parity) )?(?:suite|test|requirement|verification)`;
      return new RegExp(`(?:^|[.!?;]\\s+|\\n)\\s*(?:Correction:\\s*)?(?:${subject}) (?:is|was|has been) ${status}\\b`, 'i').test(text)
        || new RegExp(`(?:^|[.!?;]\\s+|\\n)\\s*(?:Correction:\\s*)?(?:do not|don't|never|skip|defer|cancel|withdraw) (?:run |execute |implement )?(?:${subject})\\b`, 'i').test(text)
        || new RegExp(`^\\s*\\| ${id} \\| ${status} \\|`, 'im').test(text)
        || new RegExp(`(?:^|\\n)(?:Correction:\\s*)?legacyAuthFlow\\(\\) is (?:changed|rewritten|modified) before ${id}\\b`, 'i').test(text);
    };
    const framed = (value: string) => extractionSourceOwner(value) || conditional.test(assessment(value, 'T[1-9]\\d*'));
    if (framed(body) || inactive(body, 'T[1-9]\\d*')) continue;
    for (const table of current.filter(s => s.title === 'Tests to add (every GAP above)')) {
      const text = table.body.join('\n');
      const baseline = /^\| ([A-Za-z][\w/.-]*\.test\.[jt]s) \| unit, CRITICAL \| recorded fixture outputs unchanged \|$/m.exec(text);
      const parity = new RegExp(`^\\| ([A-Za-z][\\w/.-]*\\.test\\.[jt]s) \\| integration, CRITICAL \\| legacy and ${rule[1]} agree on every fixture \\|$`, 'm').exec(text);
      if (!baseline || !parity || framed(text) || inactive(text, 'T[1-9]\\d*') ||
          !snapshotSource.includes(baseline[0]) || !snapshotSource.includes(parity[0])) continue;
      for (const tasks of current.filter(s => s.title === 'Implementation Tasks')) {
        const taskBody = tasks.body.join('\n').trim(), blocks = taskBody.split(/\n(?=-\s)/);
        const ids = blocks.map(b => /^- (?:\[[ xX]\] )?(T[1-9]\d*)\b/.exec(b)?.[1]).filter(Boolean);
        if (ids.length !== new Set(ids).size) continue;
        for (const task of blocks) {
          const match = new RegExp(`^- (?:\\[[ xX]\\] )?(T[1-9]\\d*)(?: \\([^\\n)]*\\))? [—–-] tests [—–-] CRITICAL regression fixtures for legacyAuthFlow\\(\\) and parity test against ${rule[1]}[\\t ]*(?:\\n|$)`).exec(task);
          if (!match) continue;
          const files = [...task.matchAll(/^\s+- Files: ([^\n]+)$/gm)], verifies = [...task.matchAll(/^\s+- Verify: ([^\n]+)$/gm)];
          const names = files[0]?.[1]?.split(', ').sort();
          const before = taskBody.slice(0, taskBody.indexOf(task)).trim().split('\n').at(-1) ?? '';
          if (files.length !== 1 || verifies.length !== 1 || JSON.stringify(names) !== JSON.stringify([baseline[1], parity[1]].sort()) ||
              verifies[0]![1] !== 'both suites green before and after the rewrite' || framed(before) || framed(task) ||
              inactive(task, match[1]!) || !snapshotSource.includes(task.replace(/\s+/g, ' ').trim())) continue;
          if (!current.some(s => inactive(s.body.join('\n'), match[1]!, true))) return true;
        }
      }
    }
  }

  return hasRetainedLegacyCorpus(current, snapshotSource)
    || !suiteWithdrawn && hasScheduledLegacyRegression(current, snapshotSource);
}

/** Bind a required test file to its task and a baseline run before changing the legacy code. */
function hasScheduledLegacyRegression(current: ReadonlyArray<{ title: string; body: string[] }>, snapshot: string): boolean {
  const flat = (s: string) => s.replace(/\s+/g, ' ').trim();
  const unquoted = (s: string) => s.replace(/"[^"]*"|“[^”]*”|(?<!\w)'[^'\n]*'(?!\w)|‘[^’]*’/g, '');
  const framed = (s: string) => /(?:^|\n)\s*(?:source|quoted|historical|example|if approved|once approved|when approved|pending approval|assuming approval|provided approval)\b/i.test(unquoted(s));
  const inactive = '(?:withdrawn|rejected|cancelled|canceled|deferred|optional|proposed|hypothetical|unproven|superseded|not current|no longer current|not required|no longer required|conditional on approval)';
  const approval = /\b(?:if|when|once|unless) approved|\b(?:after|pending|assuming|provided) approval\b|(?:^|\n|:\s*)(?:if|when|once|unless) accepted\b/i;
  const owned = (s: string) => snapshot.includes(flat(s)) && !framed(s)
    && !approval.test(unquoted(s))
    && !/\b(?:do not|don\x27t|never|skip|omit|defer) (?:add|write|run|capture|record|pin|implement)\b|\b(?:maybe|might|could|optional|proposed)\b/i.test(unquoted(s));
  const allTasks = current.flatMap(s => {
    const text = s.body.join('\n');
    return text.split(/\n(?=- )/).map(body => ({ body, section: s.title,
      preceding: text.slice(0, text.indexOf(body)).trim().split('\n').at(-1) ?? '',
      match: /^- (?:\[[ xX]\] )?(T[1-9]\d*)(?: \([^\n)]*\))? [—–:-] (.+)(?:\n|$)/.exec(body) }));
  });
  // Required test lists may give each suite its own inline label instead of
  // a heading. Keep that bullet's body separate from adjacent test requirements.
  const declarations: Array<{ title: string; body: string[]; inlineRequired?: boolean }> = [...current];
  for (const section of current.filter(s => /\b(?:required|mandatory) tests?\b/i.test(s.title))) {
    const blocks = section.body.join('\n').split(/\n(?=- )/);
    for (const block of blocks) {
      const match = /^- ((?:CRITICAL|MANDATORY|REQUIRED)\b[^\n]*\b(?:regression|characterization)\b[^\n]*)\n([\s\S]+)$/i.exec(block.trim());
      if (match && !framed(section.title) && owned(block) && !new RegExp(`\\b${inactive}\\b`, 'i').test(unquoted(match[1]!)))
        declarations.push({ title: match[1]!, body: [match[1]!, match[2]!], inlineRequired: true });
    }
  }
  for (const declaration of declarations) {
    const requiredRule = /\b(?:mandatory|critical|required)\b/i.test(unquoted(declaration.title));
    if (!/\b(?:regression|characterization)\b/i.test(declaration.title) || !requiredRule
        || /\b(?:not|never|no longer) (?:mandatory|critical|required)\b/i.test(declaration.title) || approval.test(unquoted(declaration.title)) || /\b(?:if|when|once|unless) accepted\b/i.test(unquoted(declaration.title))) continue;
    const body = declaration.body.join('\n').trim(), text = flat(unquoted(body));
    const files = [...text.matchAll(/\b([A-Za-z][\w/.-]*\.test(?:\.[jt]s)?)\b/g)].map(m => m[1]!);
    const beforeAndAfter = /\bmust (?:pass|be green) before and after (?:this|the) (?:refactor|rewrite|change)\b/i.test(text);
    if (!owned(body) || !/\blegacyAuthFlow\b/.test(declaration.title + ' ' + text)
        || !beforeAndAfter && !/\bbefore (?:any |the )?(?:rewrite|refactor|change)\b/i.test(text)) continue;
    // A unique task ID can carry the file and verification. The declaration
    // supplies the required old-code corpus and parity; no particular heading
    // or repeated filename/CRITICAL label is needed on the task itself.
    const declaredIds = [...new Set([...text.matchAll(/\bT[1-9]\d*\b/g)].map(m => m[0]))];
    const linkedId = declaredIds.length === 1 && /\bCRITICAL\b/.test(text)
      && current.filter(s => /\bmandatory\b/i.test(s.title) && /\bCRITICAL\b/.test(unquoted(s.body.join(' ')))
        && new RegExp(`\\b${declaredIds[0]}\\b`).test(unquoted(s.body.join(' ')))).length === 1 ? declaredIds[0] : undefined;
    const parityTargets = [...text.matchAll(/\b(?:run|execute|replay) (?:the )?same (?:corpus|suite|fixtures) (?:against|through|on) (?:the )?([A-Za-z][\w]*)(?: path)?[.;]/gi)];
    const linkedTarget = linkedId && parityTargets.length === 1
      && /\b(?:write|add|create) (?:regression|characterization)(?: \(golden\))? tests? for legacyAuthFlow\(\)/i.test(text)
      && /\bBoth must (?:produce|return|have) (?:identical|matching) (?:results|outcomes|outputs)\b/i.test(text) ? parityTargets[0]![1] : undefined;
    const scheduled = files.length === 1 && /\b(?:captures?|capturing|records?|recording|pins?|pinning)\b[^.;:]{0,180}\b(?:behavior|outcomes|outputs)\b/i.test(text);
    const comparisons = [...text.matchAll(/\b(?:asserts?|verifies?|checks?) ([A-Za-z][\w]*) (?:agrees with|matches) (?:it|(?:the )?(?:legacy )?(?:suite|baseline|outputs))\b/gi)];
    const pinnedParity = scheduled && beforeAndAfter && comparisons.length === 1 && comparisons[0]![1] !== 'legacyAuthFlow'
      && /\b(?:captures?|capturing|records?|recording|pins?|pinning) (?:the )?(?:current|prior|existing) (?:outputs|outcomes|behavior)\b/i.test(text);
    const tasks = allTasks.filter(t => linkedTarget || pinnedParity || /^Implementation Tasks$/i.test(t.section));
    for (const task of tasks) {
      if (!task.match) continue;
      const [, id, rawTitle] = task.match, title = unquoted(rawTitle!);
      if (linkedTarget && id !== linkedId) continue;
      if (tasks.filter(t => t.match?.[1] === id).length !== 1 || !/\blegacyAuthFlow\b/.test(title)
          || !/\b(?:regression|characterization)\b/i.test(title)) continue;
      const taskFiles = [...task.body.matchAll(/^  - Files: (.+)$/gm)];
      const verifies = [...task.body.matchAll(/^  - Verify: (.+)$/gm)];
      if (taskFiles.length !== 1 || verifies.length !== 1 || !owned(task.body) || framed(task.preceding)) continue;
      const verify = unquoted(verifies[0]![1]!);
      const runs = verify.split(/;\s*/);
      const linkedBaseline = linkedTarget && linkedTarget !== 'legacyAuthFlow' && id === linkedId
        && /^[A-Za-z][\w/.-]*\.test(?:\.[jt]s)?$/.test(taskFiles[0]![1]!)
        && (files.length === 0 || files.length === 1 && files[0] === taskFiles[0]![1])
        && /\b(?:write|add|create) (?:regression|characterization)(?: \(golden\))? tests? for legacyAuthFlow\(\) before (?:touching (?:it|legacyAuthFlow\(\))|(?:any |the )?(?:rewrite|refactor|change))\b/i.test(title)
        && runs.length === 2 && /^(?:the )?(?:suite|tests?|corpus) (?:passes|is green) (?:against|on) (?:legacy|legacyAuthFlow(?:\(\))?)$/i.test(runs[0]!)
        && new RegExp(`^(?:later|then) (?:passes|is green) unchanged (?:against|on) ${linkedTarget}[.]?$`, 'i').test(runs[1]!);
      const scheduledVerification = scheduled && /\bCRITICAL\b/.test(title) && taskFiles[0]![1] === files[0]
        && /\b(?:pass(?:es)?|green)\b/i.test(verify) && /\bbefore\b[^.;]*\bafter\b|\bbefore\b[^.;]*;[^.;]*\bafter\b/i.test(verify);
      // A task's explicit green baseline on unchanged code before any rewrite
      // commit is already an ordered verification; it need not be repeated in
      // a separate Verification section. The same file pins current outputs
      // in the declaration and supplies the comparison oracle for the new path.
      const committedBaseline = pinnedParity && scheduledVerification
        && tasks.filter(t => new RegExp(`^  - Files: ${files[0]!.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')}$`, 'm').test(t.body)).length === 1
        && /\b(?:passes?|green) (?:on|against) (?:main|master|(?:the )?(?:unmodified|untouched) (?:code|legacy path)) before (?:any|the) (?:refactor|rewrite|change) commit\b/i.test(verify);
      // The rule, uniquely named file/task and ordered verification together
      // establish the unchanged-code baseline without repeating CRITICAL and
      // "before" on every line of that same requirement.
      const green = (value: string) => /\b(?:pass(?:es)?|green)\b/i.test(value)
        && !/\b(?:not|never|no longer|fail(?:s|ed|ing)?|red)\b/i.test(value);
      const orderedBaseline = requiredRule && scheduled && taskFiles[0]![1] === files[0]
        && /\b(?:write|add|create|implement|record|capture|pin)\b/i.test(title)
        && runs.some(run => green(run) && /\b(?:current|unmodified|untouched) (?:code|implementation|legacy path)\b/i.test(run))
        && runs.some(run => green(run) && /\bafter (?:the )?(?:rewrite|refactor|change)\b/i.test(run))
        && /\b(?:captures?|capturing|records?|recording|pins?|pinning) (?:the )?(?:current|prior|existing) (?:outputs|outcomes|behavior)\b/i.test(text)
        && /\bmust (?:pass|satisfy) (?:the )?same (?:suite|tests|assertions) unchanged\b|\b(?:the )?same (?:suite|tests|assertions) must (?:pass|remain green) unchanged (?:after|across) (?:the )?(?:rewrite|refactor|change)\b/i.test(text)
        && tasks.filter(t => new RegExp(`^  - Files: ${files[0]!.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')}$`, 'm').test(t.body)).length === 1
        && current.filter(s => /^Verification(?: \([^)]*\))?$/i.test(s.title)).some(s => {
          const steps = s.body.join('\n').trim().split(/\n(?=\d+[.)] )/);
          const first = unquoted(steps[0] ?? '').trim();
          return steps.length >= 2 && owned(steps[0]!) && /^1[.)] (?:run|execute|test|verify)\b/i.test(first)
            && new RegExp(`\\b${id}\\b`).test(first) && /\b(?:unmodified|untouched) (?:code|implementation|legacy path)\b/i.test(first) && green(first)
            && steps.slice(1).some(step => {
              const statement = unquoted(step).trim();
              return owned(step) && /^(?:[2-9]|[1-9]\\d+)[.)] (?:re-run|rerun|run|execute)\b/i.test(statement)
                && new RegExp(`\\b${id}\\b`).test(statement) && /\bafter (?:the )?(?:rewrite|refactor|change)\b/i.test(statement)
                && green(statement) && /\bunchanged\b/i.test(statement);
            });
        });
      const inlineBaseline = declaration.inlineRequired && scheduled && taskFiles[0]![1] === files[0]
        && tasks.filter(t => new RegExp(`^  - Files: ${files[0]!.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')}$`, 'm').test(t.body)).length === 1
        && [...text.matchAll(/\bT[1-9]\d*\b/g)].every(m => m[0] === id)
        && new RegExp(`\\b${id}\\b`).test(text)
        && /\b(?:run|execute|replay) (?:the )?same fixtures\b/i.test(text)
        && /\bagainst (?:the )?new path\b/i.test(text)
        && /\bassert (?:identical|matching)\b[^.;]*\b(?:outputs?|outcomes?|session shape)\b/i.test(text)
        && /\b(?:rejection|error) (?:class|kind|code)\b/i.test(text)
        && runs.some(run => green(run) && /\bon (?:the )?legacy(?: path)? before (?:any|the) (?:refactor|rewrite|change)(?: commit)?\b/i.test(run))
        && runs.some(run => green(run) && /\bon both paths\b/i.test(run))
        && current.filter(s => /^Verification(?: \([^)]*\))?$/i.test(s.title)).some(s => {
          const first = unquoted(s.body.join('\n').trim().split(/\n(?=\d+[.)] )/)[0] ?? '');
          return owned(first) && /^1[.)] (?:run|execute|test|verify)\b/i.test(first)
            && new RegExp(`\\b${id}\\b`).test(first) && /\b(?:untouched|unmodified) legacy path\b/i.test(first)
            && /\bfirst\b/i.test(first);
        });
      const scopedBaseline = linkedBaseline || committedBaseline || orderedBaseline || inlineBaseline;
      if (!scopedBaseline && !scheduledVerification) continue;
      // An explicit ordered step provides the old-code oracle; matching a task label alone cannot.
      const baseline = scopedBaseline || current.filter(s => /^Verification(?: \([^)]*\))?$/i.test(s.title)).some(s => {
        const lines = s.body.join('\n').split(/\n(?=\d+\. )/);
        return lines.some(line => {
          const statement = unquoted(line);
          return /^\d+\. (?:Write|Run|Execute|Add|Create)\b/i.test(statement) && owned(line) && new RegExp(`\\b${id}\\b`).test(statement)
            && /\blegacyAuthFlow\b/.test(statement) && /\b(?:untouched|unmodified)\b/.test(statement)
            && /\b(?:must (?:pass|be green)|commit it green)\b/i.test(statement)
            && /\bbefore\b|\bfirst\b/i.test(statement);
        });
      });
      if (!baseline) continue;
      const subject = `(?:${id}(?: (?:baseline )?verification)?|(?:this|the) (?:(?:legacy|baseline) )?(?:(?:regression|characterization) )?(?:suite|test|requirement|verification))`;
      const cancelled = current.some(s => {
        if (/\b(?:history|historical|source|quoted|example)\b/i.test(s.title)) return false;
        const named = /^(.*?)\b(?:regression|characterization)\s+(?:suite|tests?)\b/i.exec(s.title)?.[1]?.trim();
        const foreign = Boolean(named && !/^(?:(?:current|final|critical|required|updated)\s*)*(?:legacy(?:AuthFlow\(\))?)?[\s:—-]*$/i.test(named));
        const raw = s.body.join('\n').replace(new RegExp(`(${subject} (?:is|was|has been) )["“'‘](${inactive})["”'’]`, 'gi'), '$1$2');
        return unquoted(raw).split(/\n|[.!?;]\s+/).some(line => {
          if (framed(line) || /^\s*(?:if|unless|assuming|provided)\b/i.test(line)) return false;
          if (foreign && !new RegExp(`\\b${id}\\b|legacyAuthFlow|\\blegacy (?:regression|characterization)`).test(line)) return false;
          return new RegExp(`\\b${subject} (?:is|was|has been) ${inactive}\\b|^\\s*\\|\\s*${id}\\s*\\|\\s*${inactive}\\s*\\|`, 'i').test(line)
            || new RegExp(`^\\s*(?:Correction:\\s*)?(?:do not|don't|never|skip|defer|cancel|withdraw) (?:run |execute |implement )?${subject}\\b`, 'i').test(line)
            || new RegExp(`\\b(?:run|execute|record|capture) ${id} only after (?:modifying|changing|rewriting|refactoring|removing|deleting) legacyAuthFlow\\b`, 'i').test(line)
            || new RegExp(`\\blegacyAuthFlow\\(\\) (?:is|was|has been|will be) (?:modified|changed|rewritten|refactored|removed|deleted) before ${id}\\b`, 'i').test(line)
            || Boolean(scopedBaseline && new RegExp(`\\b(?:update|change|replace|regenerate|rewrite) ${subject} (?:expectations|expected (?:results|outputs)|assertions)\\b|\\b${subject} (?:expectations|assertions) (?:are|will be) (?:changed|updated|replaced)\\b`, 'i').test(line));
        });
      });
      if (!cancelled) return true;
    }
  }
  return false;
}

function regressionEvidence(text: string): boolean {
  if (declaredLegacyCharacterization(text)) return true;
  return prose(text).split(/\n\s*\n|\n(?=\s*[-#])/).some(block => {
    let task = block.trim().replace(/^[-+]\s+(?:\[[ xX]\]\s*)?/, '');
    const numbered = /^T\d+(?:\s*\([^\n)]*\))?\s*[—–:-]\s*/.exec(task);
    if (numbered) {
      // A numbered task may place a simple component path before its action.
      // Do not remove arbitrary prose or let this metadata assign the test target.
      task = task.slice(numbered[0].length)
        .replace(/^[A-Za-z][A-Za-z0-9_-]*(?:\/[A-Za-z][A-Za-z0-9_-]*)+[\t ]+[—–][\t ]+/, '');
    }
    if (requiredLegacyCharacterization(task)) return true;
    const legacySubject = /^legacyAuthFlow(?:\(\))?\s*[—–:-]\s*/i;
    const action = task.replace(legacySubject, '');
    const instruction = action.match(/^(?:(?:I|we)\s+)?(?:add(?:ed)?|record(?:ed)?|write|wrote|require(?:d)?|include(?:d)?)\s+((?:(?:a|the|new|required|legacyAuthFlow(?:\(\))?|regression|characterization|baseline|prior-behavior)\s+)*(?:tests?|fixtures?|suites?))\b([^.;\n]*)/i);
    const explicitTarget = instruction && /^\s+(?:for|of|covering|characterizing|pinning)\b/i.test(instruction[2]!);
    const legacyTarget = instruction && (
      /^\s+(?:for|of|covering|characterizing)\s+(?:the\s+)?(?:prior behavior of\s+)?legacyAuthFlow\b/i.test(instruction[2]!) ||
      /^\s+pinning\s+(?:the\s+)?legacyAuthFlow(?:\(\))?(?:'s)?\s+(?:current|existing|prior)\s+behavior\b/i.test(instruction[2]!));
    const target = instruction && (!explicitTarget || legacyTarget) &&
      (legacySubject.test(task) || /\blegacyAuthFlow\b/.test(instruction[1]!) || legacyTarget);
    // An affirmative task or completed addition, not an example, quotation,
    // conditional proposal or an uncertain discussion of whether to add it.
    return Boolean(target) &&
    /\b(?:regression|characterization)\b/i.test(instruction![0]) &&
    /\b(?:before|prior behavior|parity|compatibility|characterization)\b/i.test(instruction![0]) &&
    !/\b(?:no|not|never|skip\w*|defer\w*|maybe|might|could|if|unless|optional)\b/i.test(block);
  });
}

export function evaluateEngSeedCoverage(transcript: PlanCountTranscript, plan: string,
  startedAt: number, finishedAt: number) {
  const decisions: Partial<Record<Seed, string>> = {};
  const problems: string[] = [];
  const sessions = new Set(transcript.calls.map(c => c.sessionId));
  const identities = transcript.calls.map(c => `${c.sessionId}:${c.toolUseId}`);
  const bound = transcript.status === 'ready' && sessions.size === 1 && !sessions.has('') &&
    identities.length === new Set(identities).size && Number.isFinite(startedAt) &&
    Number.isFinite(finishedAt) && startedAt <= finishedAt;
  if (!bound) problems.push('missing, ambiguous or unbound native transcript');
  if (bound) for (const call of transcript.calls) {
    if (!completedDecision(call, startedAt, finishedAt)) continue;
    const seeds = call.questions.flatMap(seedSubjects);
    // One combined approval cannot replace separate decisions for independent seeds.
    // An unrelated, separately answered setup tab may accompany the one seed;
    // multiple seeded questions still cannot lend this call ID to several seeds.
    if (seeds.length === 1) decisions[seeds[0]!] ??= `${call.sessionId}:${call.toolUseId}`;
  }
  const missing = ENG_DECISION_SEEDS.filter(seed => !decisions[seed]);
  const regression = regressionEvidence(plan) ? 'plan' : bound && transcript.assistantMessages.some(m =>
    sessions.has(m.sessionId) && Date.parse(m.timestamp) >= startedAt && Date.parse(m.timestamp) <= finishedAt &&
    regressionEvidence(m.text)) ? 'public-narration' : undefined;
  if (!regression) problems.push('mandatory legacy regression coverage absent');
  // The caller also retains the existing fresh owned-path/native completion and D19 checks.
  if (!/^## GSTACK REVIEW REPORT[\t ]*\n\s*\S/m.test(prose(plan))) problems.push('final review report absent or empty');
  return { ok: bound && missing.length === 0 && problems.length === 0, decisions, missing, regression, problems };
}