fix: delete AskUserQuestion fallback (root cause of forever war)

The /plan-eng-review skill failed to fire AskUserQuestion on a real
plan review and surfaced 4 calibration decisions via prose instead.
Investigation traced this to a "fallback when neither variant is
callable" clause in the preamble that the model rationalizes around
as a general escape hatch from "fanning out round-trip AUQs," even
when an AUQ variant IS callable. Codex review confirmed the fallback
exists in 8 inline sites with 2 surviving escape hatches the original
narrowing missed (a "genuinely trivial" exception duplicated across
all 4 plan-* templates, and a "outside plan mode, output as prose
and stop" branch in the preamble itself).

Net deletion in skill text. Closes both branches of the deleted
fallback (plan-file write AND prose-and-stop) and the trivial-fix
exception with a single hard rule:

  If no AskUserQuestion variant appears in your tool list, this
  skill is BLOCKED. Stop, report `BLOCKED — AskUserQuestion
  unavailable`, and wait for the user.

Honest about being a model directive, not a runtime guard — none of
the PTY harness helpers enforce BLOCKED today. The architectural
improvement is that the model has fewer alternatives to obey it
against. Runtime enforcement is a follow-up TODO.

Sources changed:
- scripts/resolvers/preamble/generate-ask-user-format.ts: delete both
  fallback branches; replace with 1-line BLOCKED rule
- scripts/resolvers/preamble/generate-completion-status.ts: delete
  fallback in generatePlanModeInfo
- plan-eng-review/SKILL.md.tmpl: delete fallback at Step 0 + Sections
  1-4 (5 instances) + delete trivial-fix exception
- office-hours/SKILL.md.tmpl: delete fallback in approach-selection
- plan-ceo-review/SKILL.md.tmpl: delete trivial-fix exception
- plan-design-review/SKILL.md.tmpl: delete trivial-fix exception
- plan-devex-review/SKILL.md.tmpl: delete trivial-fix exception

Generated SKILL.md regen lands in a follow-up commit per the bisect
convention (template changes separate from regenerated output).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plan-eng-review/SKILL.md.tmpl

@@ -113,7 +113,7 @@ Before reviewing anything, answer these questions:
    - How will users download or install it (GitHub Releases, package manager, container registry)?
    If the plan defers distribution, flag it explicitly in the "NOT in scope" section — don't let it silently drop.
 
-If the complexity check triggers (8+ files or 2+ new classes/services), STOP before any review-section work. Call AskUserQuestion: name what's overbuilt, propose a minimal version that achieves the core goal, ask whether to reduce or proceed as-is. The AskUserQuestion call is a tool_use, not prose — call the tool directly. If no AskUserQuestion variant is callable, follow the preamble's "Tool resolution" fallback: in plan mode, write `## Decisions to confirm` into the plan file and ExitPlanMode; outside plan mode, output the decision brief as prose and stop. Never silently auto-decide.
+If the complexity check triggers (8+ files or 2+ new classes/services), STOP before any review-section work. Call AskUserQuestion: name what's overbuilt, propose a minimal version that achieves the core goal, ask whether to reduce or proceed as-is. The AskUserQuestion call is a tool_use, not prose — call the tool directly.
 
 **STOP.** Do NOT proceed to Section 1 (Architecture review), edit the plan file with a proposed scope reduction, or call ExitPlanMode until the user responds. Naming the 80% solution in chat prose and continuing — or loading the AskUserQuestion schema via ToolSearch and then never invoking it — is the failure mode this gate exists to prevent.
 
@@ -142,7 +142,7 @@ Evaluate:
 * For each new codepath or integration point, describe one realistic production failure scenario and whether the plan accounts for it.
 * **Distribution architecture:** If this introduces a new artifact (binary, package, container), how does it get built, published, and updated? Is the CI/CD pipeline part of the plan or deferred?
 
-For each issue found in this section, call AskUserQuestion individually. One issue per call. Present options, state your recommendation, explain WHY. Do NOT batch multiple issues into one AskUserQuestion. Use the preamble's AskUserQuestion Format section. The AskUserQuestion call is a tool_use, not prose — call the tool directly. If no AskUserQuestion variant is callable in this session, follow the preamble's "Tool resolution" fallback: in plan mode, write `## Decisions to confirm` into the plan file and ExitPlanMode; outside plan mode, output the decision brief as prose and stop. Never silently auto-decide.
+For each issue found in this section, call AskUserQuestion individually. One issue per call. Present options, state your recommendation, explain WHY. Do NOT batch multiple issues into one AskUserQuestion. Use the preamble's AskUserQuestion Format section. The AskUserQuestion call is a tool_use, not prose — call the tool directly.
 
 **STOP.** Do NOT proceed to the next review section, edit the plan file with the proposed fix, or call ExitPlanMode until the user responds. An issue with an "obvious fix" is still an issue and still needs explicit user approval before it lands in the plan. Loading the AskUserQuestion schema via ToolSearch and then writing the recommendation as chat prose is the failure mode this gate exists to prevent.
 
@@ -157,7 +157,7 @@ Evaluate:
 * Areas that are over-engineered or under-engineered relative to my preferences.
 * Existing ASCII diagrams in touched files — are they still accurate after this change?
 
-For each issue found in this section, call AskUserQuestion individually. One issue per call. Present options, state your recommendation, explain WHY. Do NOT batch multiple issues into one AskUserQuestion. Use the preamble's AskUserQuestion Format section. The AskUserQuestion call is a tool_use, not prose — call the tool directly. If no AskUserQuestion variant is callable in this session, follow the preamble's "Tool resolution" fallback: in plan mode, write `## Decisions to confirm` into the plan file and ExitPlanMode; outside plan mode, output the decision brief as prose and stop. Never silently auto-decide.
+For each issue found in this section, call AskUserQuestion individually. One issue per call. Present options, state your recommendation, explain WHY. Do NOT batch multiple issues into one AskUserQuestion. Use the preamble's AskUserQuestion Format section. The AskUserQuestion call is a tool_use, not prose — call the tool directly.
 
 **STOP.** Do NOT proceed to the next review section, edit the plan file with the proposed fix, or call ExitPlanMode until the user responds. An issue with an "obvious fix" is still an issue and still needs explicit user approval before it lands in the plan. Loading the AskUserQuestion schema via ToolSearch and then writing the recommendation as chat prose is the failure mode this gate exists to prevent.
 
@@ -167,7 +167,7 @@ For each issue found in this section, call AskUserQuestion individually. One iss
 
 For LLM/prompt changes: check the "Prompt/LLM changes" file patterns listed in CLAUDE.md. If this plan touches ANY of those patterns, state which eval suites must be run, which cases should be added, and what baselines to compare against. Then use AskUserQuestion to confirm the eval scope with the user.
 
-For each issue found in this section, call AskUserQuestion individually. One issue per call. Present options, state your recommendation, explain WHY. Do NOT batch multiple issues into one AskUserQuestion. Use the preamble's AskUserQuestion Format section. The AskUserQuestion call is a tool_use, not prose — call the tool directly. If no AskUserQuestion variant is callable in this session, follow the preamble's "Tool resolution" fallback: in plan mode, write `## Decisions to confirm` into the plan file and ExitPlanMode; outside plan mode, output the decision brief as prose and stop. Never silently auto-decide.
+For each issue found in this section, call AskUserQuestion individually. One issue per call. Present options, state your recommendation, explain WHY. Do NOT batch multiple issues into one AskUserQuestion. Use the preamble's AskUserQuestion Format section. The AskUserQuestion call is a tool_use, not prose — call the tool directly.
 
 **STOP.** Do NOT proceed to the next review section, edit the plan file with the proposed fix, or call ExitPlanMode until the user responds. An issue with an "obvious fix" is still an issue and still needs explicit user approval before it lands in the plan. Loading the AskUserQuestion schema via ToolSearch and then writing the recommendation as chat prose is the failure mode this gate exists to prevent.
 
@@ -178,7 +178,7 @@ Evaluate:
 * Caching opportunities.
 * Slow or high-complexity code paths.
 
-For each issue found in this section, call AskUserQuestion individually. One issue per call. Present options, state your recommendation, explain WHY. Do NOT batch multiple issues into one AskUserQuestion. Use the preamble's AskUserQuestion Format section. The AskUserQuestion call is a tool_use, not prose — call the tool directly. If no AskUserQuestion variant is callable in this session, follow the preamble's "Tool resolution" fallback: in plan mode, write `## Decisions to confirm` into the plan file and ExitPlanMode; outside plan mode, output the decision brief as prose and stop. Never silently auto-decide.
+For each issue found in this section, call AskUserQuestion individually. One issue per call. Present options, state your recommendation, explain WHY. Do NOT batch multiple issues into one AskUserQuestion. Use the preamble's AskUserQuestion Format section. The AskUserQuestion call is a tool_use, not prose — call the tool directly.
 
 **STOP.** Do NOT proceed to the next review section, edit the plan file with the proposed fix, or call ExitPlanMode until the user responds. An issue with an "obvious fix" is still an issue and still needs explicit user approval before it lands in the plan. Loading the AskUserQuestion schema via ToolSearch and then writing the recommendation as chat prose is the failure mode this gate exists to prevent.
 
@@ -201,7 +201,7 @@ Follow the AskUserQuestion format from the Preamble above. Additional rules for
 * **Map the reasoning to my engineering preferences above.** One sentence connecting your recommendation to a specific preference (DRY, explicit > clever, minimal diff, etc.).
 * Label with issue NUMBER + option LETTER (e.g., "3A", "3B").
 * **Coverage vs kind:** for every per-issue AskUserQuestion you raise in this review, decide whether the options differ in coverage or in kind. If coverage (e.g., more tests vs fewer, complete error handling vs happy-path-only, full edge-case coverage vs shortcut), include `Completeness: N/10` on each option. If kind (e.g., architectural choice between two different systems, posture-over-posture, A/B/C where each is a different kind of thing), skip the score and add one line: `Note: options differ in kind, not coverage — no completeness score.` Do NOT fabricate scores on kind-differentiated questions — filler scores are worse than no score.
-* **Escape hatch (tightened):** If a section has zero findings, state "No issues, moving on" and proceed. If it has findings, use AskUserQuestion for each — a finding with an "obvious fix" is still a finding and still needs user approval before any change lands in the plan. Only skip AskUserQuestion when the decision is genuinely trivial (e.g., a typo fix) AND there are no meaningful alternatives. When in doubt, ask.
+* **Zero findings:** if a section has zero findings, state "No issues, moving on" and proceed. Otherwise, use AskUserQuestion for each finding — a finding with an "obvious fix" is still a finding and still needs user approval before any change lands in the plan.
 
 ## Required outputs