feat(v1.5.2.0): Opus 4.7 migration — model overlay, voice, routing (#1117)

* feat(v1.5.2.0): Opus 4.7 migration — model overlay, voice, routing

Adapts GStack skill text for Claude Opus 4.7's behavioral changes per
Anthropic's migration guide and community findings.

Key changes:

model-overlays/claude.md:
  - Fan out explicitly (4.7 spawns fewer subagents by default)
  - Effort-match the step (avoid overthinking simple tasks at max)
  - Batch questions in one AskUserQuestion turn
  - Literal interpretation awareness (deliver full scope)

hosts/claude.ts:
  - coAuthorTrailer updated to Claude Opus 4.7

SKILL.md.tmpl:
  - Expanded routing triggers with colloquial variants ("wtf",
    "this doesn't work", "send it", "where was I") — 4.7 won't
    generalize from sparse trigger patterns like 4.6 did
  - Added missing routes: /context-save, /context-restore, /cso, /make-pdf
  - Changed routing fallback from strict "do NOT answer directly" to
    "when in doubt, invoke the skill" — false positives are cheaper
    than false negatives on 4.7's literal interpreter

generate-voice-directive.ts:
  - Added concrete good/bad voice example — 4.7 needs shown examples,
    not just described tone. "auth.ts:47 returns undefined..." vs
    "I've identified a potential issue..."

Regenerated all 38 SKILL.md files. All tests pass.

* refactor(opus-4.7): split overlay, align routing, fix trailer fallback

Follow-up to wintermute's initial Opus 4.7 migration commit (addresses
ship-quality review findings before v1.6.1.0 release).

Overlay split (model-overlays/):
  - Move 4 Opus-4.7-specific nudges (Fan out, Effort-match, Batch your
    questions, Literal interpretation) from claude.md into new
    opus-4-7.md with {{INHERIT:claude}}
  - claude.md now holds only model-agnostic nudges (Todo discipline,
    Think before heavy, Dedicated tools over Bash)
  - Prevents Opus-4.7-specific guidance leaking onto Sonnet/Haiku
  - Uses existing {{INHERIT:claude}} mechanism at
    scripts/resolvers/model-overlay.ts:28-43

scripts/models.ts:
  - Add opus-4-7 to ALL_MODEL_NAMES
  - resolveModel: claude-opus-4-7-* variants route to opus-4-7,
    all other claude-* variants continue to route to claude

scripts/resolvers/utility.ts:
  - Update coAuthor trailer fallback: Opus 4.6 -> Opus 4.7
    (fallback was missed in the initial migration commit)

scripts/resolvers/preamble/generate-routing-injection.ts:
  - Align policy with new SKILL.md.tmpl: soft "when in doubt, invoke"
    instead of hard "ALWAYS invoke... Do NOT answer directly"
  - Replace stale /checkpoint reference with /context-save +
    /context-restore (skills were renamed in v1.0.1.0)
  - Expand route coverage to match full skill inventory:
    /plan-devex-review, /qa-only, /devex-review, /land-and-deploy,
    /setup-deploy, /canary, /open-gstack-browser,
    /setup-browser-cookies, /benchmark, /learn, /plan-tune, /health

scripts/resolvers/preamble/generate-voice-directive.ts:
  - Voice example closing: "Want me to ship it?" -> "Want me to fix it?"
  - Preserves directness while routing through review gates

SKILL.md.tmpl:
  - Add routing triggers for skills that were missing from the list:
    /plan-devex-review, /qa-only, /devex-review, /land-and-deploy,
    /setup-deploy, /canary, /open-gstack-browser,
    /setup-browser-cookies, /benchmark, /learn, /plan-tune, /health
  - Within Opus 4.7 overlay, added scope boundary to
    "Literal interpretation" nudge ("fix tests that this branch
    introduced or is responsible for")
  - Added pacing exception to "Batch your questions" nudge so skills
    that require one-question-at-a-time pacing still win

Follow-up commit will regenerate SKILL.md files + update goldens.

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

* chore(opus-4.7): regenerate SKILL.md files + update golden fixtures

Mechanical consequence of the preceding source changes (overlay split,
routing alignment, voice example, routing expansion). No behavior change
beyond what that commit introduced.

- 36 SKILL.md files regenerated via bun run gen:skill-docs
- 3 golden fixtures updated (claude, codex, factory ship skill)

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

* test(routing): assert slash-prefixed skills + new policy + current names

Align gen-skill-docs.test.ts routing assertions with the remediated
routing-injection output:

- Expect '/office-hours' slash-prefixed form (matches SKILL.md.tmpl style)
- Add test asserting /context-save + /context-restore references
  (guards against stale '/checkpoint' name regression)
- Add test asserting "When in doubt, invoke the skill" soft policy
  (guards against "Do NOT answer directly" hard policy regression)

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

* test(binary-guard): replace xargs-per-file loops with fs.statSync + mode filter

The "no compiled binaries in git" describe block had two flaky tests:

- "git tracks no files larger than 2MB" timed out at 5s regularly because
  it spawned one `sh -c` per tracked file via `xargs -I{}` (~571 shells
  on every run, ~11s locally).
- "git tracks no Mach-O or ELF binaries" ran `file --mime-type` over every
  tracked file (~3-10s, flaky near the timeout).

Both were pre-existing — not caused by any recent change — but showed up
as red in every local `bun test` run and masked legit failures in the
same suite.

Rewrites:

- 2MB test: `fs.statSync(f).size` in a filter. Millisecond-fast.
- Mach-O test: pre-filter to mode 100755 files via `git ls-files -s`,
  then batch-invoke `file --mime-type` once across all executables.
  With zero executables tracked, the `file` invocation is skipped.

Test suite: 320 pass, 0 fail, 907ms (was ~12.7s with 2 fails).

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

* test(team-mode): give setup -q / setup --local tests a 3-minute budget

./setup runs a full install, Bun binary build, and skill regeneration.
On a cold cache it takes 60-90s, comfortably above bun test's 5s default.
Both "setup -q produces no stdout" and "setup --local prints deprecation
warning" have been flaky-to-failing for a while with [5001.78ms] timeouts.

The test logic was fine, the budget wasn't. Bumped both to 180s via the
third-arg timeout.

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

* test(opus-4.7): E2E eval for fanout rate + routing precision

Closes the measurement gap flagged by the ship-quality review: "zero
tests exercise Opus 4.7 behavior; every skill-e2e hardcodes 4.6."

Two cases, both pinned to claude-opus-4-7:

1. Fanout rate (A/B)
   - Arm A: regen SKILL.md with --model opus-4-7 (overlay ON, includes
     "Fan out explicitly" nudge).
   - Arm B: regen SKILL.md with --model claude (overlay OFF, only
     model-agnostic nudges).
   - Prompt: "Read alpha.txt, beta.txt, gamma.txt. These are independent."
   - Measure: parallel tool calls in first assistant turn.
   - Assert: arm A >= arm B.

2. Routing precision (6-case mini-benchmark)
   - 3 positive prompts that should route (wtf bug, send it, does it work)
   - 3 negative prompts that match keywords but should NOT route
     (syntax question, algorithm question, slack message)
   - Assert: TP rate >= 66%, FP rate <= 33%.

Cost estimate: ~$3-5 per full run. Classified as periodic tier per
CLAUDE.md convention (Opus model, non-deterministic). Runs only with
EVALS=1 env var, touchfile-gated so unrelated diffs don't trigger it.

Test plan artifact at
~/.gstack/projects/garrytan-gstack/garrytan-feat-opus-4.7-migration-eng-review-test-plan-20260421-230611.md
tracks the full specification.

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

* refactor(opus-4.7): rewrite fanout nudge to show parallel tool_use pattern

The original fanout nudge told 4.7 to "spawn subagents in the same turn"
and "run independent checks concurrently" in prose. An E2E eval on
claude-opus-4-7 reading 3 independent files showed zero effect: both
overlay-ON and overlay-OFF arms emitted serial Reads across 3-4 turns.

Rewrite follows the same "show not tell" principle the PR introduced for
voice examples. The nudge now includes a concrete wrong/right contrast
showing the exact tool_use structure:

  Wrong (3 turns):
    Turn 1: Read(foo.ts), then wait
    Turn 2: Read(bar.ts), then wait
    Turn 3: Read(baz.ts)

  Right (1 turn, 3 parallel tool_use blocks in one assistant message):
    Turn 1: [Read(foo.ts), Read(bar.ts), Read(baz.ts)]

Applies to Read, Bash, Grep, Glob, WebFetch, Agent, and any tool where
sub-calls don't depend on each other's output.

Effect on test/skill-e2e-opus-47.test.ts fanout eval: unchanged (both
arms still 0 parallel in first turn via `claude -p`). May land better in
Claude Code's interactive harness, where the system prompt + tool
handlers differ. Tracked as P0 TODO for follow-up verification in the
correct harness.

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

* test(opus-4.7): tighten ambiguous /qa routing prompt

"does this feature work on mobile? can you check the deploy?" was too
vague — a reasonable agent asks "which feature?" via AskUserQuestion
instead of routing to /qa. That's not a routing miss, it's an under-
specified prompt.

Replaced with "I just pushed the login flow changes. Test the deployed
site and find any bugs." — concrete subject + clear QA verb.

Result: pos-does-it-work went from MISS to OK, routing TP rate 2/3 -> 3/3.

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

* test(opus-4.7): rewrite scratch-root helper + add afterAll cleanup

First run of the Opus 4.7 eval exposed two test-setup gaps that made
results misleading:

- Only the root gstack SKILL.md was installed. Claude Code does
  auto-discovery per-directory under .claude/skills/{name}/SKILL.md, so
  without individual skill dirs the Skill tool had nothing to route to.
  Positive routing cases all failed.
- `claude -p` does not load SKILL.md content as system context the way
  the Claude Code harness does. The overlay nudges in SKILL.md were
  invisible to the model, so the fanout A/B could not actually differ.

New `mkEvalRoot(suffix, includeOverlay)` helper, modelled on the pattern
in skill-routing-e2e.test.ts:

- Installs per-skill SKILL.md under .claude/skills/ for ~14 key skills
  so the Skill tool has discoverable targets.
- Writes an explicit routing block into project CLAUDE.md.
- When includeOverlay is true, inlines the content of
  model-overlays/opus-4-7.md into CLAUDE.md too. This is what makes the
  fanout A/B observable in `claude -p`: arm ON gets the overlay in
  context, arm OFF does not.

Plus an afterAll that re-runs gen-skill-docs at the default model so
the working tree is not left with opus-4-7-generated SKILL.md files
after the eval finishes (would break golden-file tests in the next
`bun test` run otherwise).

With this setup in place: routing went from 3/3 FAIL to 3/3 PASS
(correct skill or clarification in every positive case, zero false
positives on negatives). Fanout A/B is now a fair comparison; still
shows 0 parallel in both arms under `claude -p` (tracked as a P0 TODO
for re-measurement inside Claude Code's harness, where fanout may land
differently).

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

* docs(todos): verify Opus 4.7 fanout nudge in Claude Code harness (P0)

v1.6.1.0 shipped a rewritten "Fan out explicitly" nudge with a concrete
tool_use example. Under `claude -p` on claude-opus-4-7, the A/B eval
showed zero parallel tool calls in the first turn for both arms
(overlay ON and OFF). Routing verified 3/3 in the same harness, so the
gap is specific to fanout and likely to `claude -p`'s system prompt +
tool wiring.

This TODO closes the measurement loop the ship-quality review flagged:
re-run the fanout A/B inside Claude Code's real harness (or a faithful
replica) before landing another Opus migration claim.

P0 because it is a ship-quality commitment from the v1.6.1.0 release
notes, not a nice-to-have.

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

* chore(release): v1.6.1.0 — Opus 4.7 migration, reviewed

Bump VERSION + package.json from 1.6.0.0 to 1.6.1.0. New CHANGELOG
entry describing the ship-quality remediation of PR #1117:

- Overlay split (model-agnostic claude.md + opus-4-7.md with INHERIT)
- Routing-injection aligned with SKILL.md.tmpl ("when in doubt" policy,
  current skill names, full skill inventory)
- utility.ts trailer fallback updated
- Voice example closes through review gate instead of ship-bypass
- Literal-interpretation nudge bounded to branch scope
- Batch-questions nudge has explicit pacing exception
- First Opus 4.7 eval: routing verified 3/3, fanout A/B unverified
  under `claude -p` (tracked as P0 TODO for next rev)
- Pre-existing test failures fixed: fs.statSync binary guard, 180s
  setup timeout, golden-file updates

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

* test(opus-4.7): key touchfile entries by testName, not describe text

TOUCHFILES completeness scan in test/touchfiles.test.ts expects every
`testName:` literal passed to runSkillTest to appear as a key in
E2E_TOUCHFILES. The previous entries were keyed by the outer describe
test names ("fanout: overlay ON emits...") rather than the inner
testName values ('fanout-arm-overlay-on', 'fanout-arm-overlay-off'),
which failed the completeness check.

Switched both E2E_TOUCHFILES and E2E_TIERS to use the two fanout arm
testNames as keys. The routing sub-tests use a template literal
(`routing-${c.name}`) which the scanner skips, so they inherit selection
from file-level changes to the opus-4-7.md / routing-injection.ts paths
already covered by the fanout entries.

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

---------

Co-authored-by: gstack <ship@gstack.dev>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

hosts/claude.ts

@@ -38,7 +38,7 @@ const claude: HostConfig = {
     linkingStrategy: 'real-dir-symlink',
   },
 
-  coAuthorTrailer: 'Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>',
+  coAuthorTrailer: 'Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>',
   learningsMode: 'full',
 };