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>

model-overlays/claude.md

@@ -8,27 +8,3 @@ the user course-correct cheaply instead of mid-flight.
 
 **Dedicated tools over Bash.** Prefer Read, Edit, Write, Glob, Grep over shell
 equivalents (cat, sed, find, grep). The dedicated tools are cheaper and clearer.
-
-**Fan out explicitly.** Opus 4.7 defaults to sequential work and spawns fewer
-subagents than 4.6. When a task has independent sub-problems (investigating multiple
-files, testing multiple endpoints, auditing multiple components), explicitly parallelize:
-spawn subagents in the same turn, run independent checks concurrently, don't serialize
-work that has no dependencies. If you catch yourself doing A then B then C where none
-depend on each other, stop and do all three at once.
-
-**Effort-match the step.** Simple file reads, config checks, command lookups, and
-mechanical edits don't need deep reasoning. Complete them quickly and move on. Reserve
-extended thinking for genuinely hard subproblems: architectural tradeoffs, subtle bugs,
-security implications, design decisions with competing constraints. Over-thinking
-simple steps wastes tokens and time.
-
-**Batch your questions.** If you need to clarify multiple things before proceeding,
-ask all of them in a single AskUserQuestion turn. Do not drip-feed one question per
-turn. Three questions in one message beats three back-and-forth exchanges.
-
-**Literal interpretation awareness.** Opus 4.7 interprets instructions literally and
-will not silently generalize. When the user says "fix the tests," fix ALL failing tests,
-not just the first one. When the user says "update the docs," update every relevant doc,
-not just the most obvious one. Read the full scope of what was asked and deliver the
-full scope. If the request is ambiguous, ask once (batched with any other questions),
-then execute completely.

model-overlays/opus-4-7.md

@@ -0,0 +1,29 @@
+{{INHERIT:claude}}
+
+**Fan out explicitly.** Opus 4.7 defaults to sequential work and spawns fewer
+subagents than 4.6. When a task has independent sub-problems (investigating multiple
+files, testing multiple endpoints, auditing multiple components), explicitly parallelize:
+spawn subagents in the same turn, run independent checks concurrently, don't serialize
+work that has no dependencies. If you catch yourself doing A then B then C where none
+depend on each other, stop and do all three at once.
+
+**Effort-match the step.** Simple file reads, config checks, command lookups, and
+mechanical edits don't need deep reasoning. Complete them quickly and move on. Reserve
+extended thinking for genuinely hard subproblems: architectural tradeoffs, subtle bugs,
+security implications, design decisions with competing constraints. Over-thinking
+simple steps wastes tokens and time.
+
+**Batch your questions.** If you need to clarify multiple things before proceeding,
+ask all of them in a single AskUserQuestion turn. Do not drip-feed one question per
+turn. Three questions in one message beats three back-and-forth exchanges. Exception:
+skill workflows that explicitly require one-question-at-a-time pacing (e.g., plan
+review skills with "STOP. AskUserQuestion once per issue. Do NOT batch.") override this
+nudge. The skill wins on pacing, always.
+
+**Literal interpretation awareness.** Opus 4.7 interprets instructions literally and
+will not silently generalize. When the user says "fix the tests," fix all failing tests
+that this branch introduced or is responsible for, not just the first one (and not
+pre-existing failures in unrelated code). When the user says "update the docs," update
+every relevant doc in scope, not just the most obvious one. Read the full scope of what
+was asked and deliver the full scope. If the request is ambiguous or the scope is
+unclear, ask once (batched with any other questions), then execute completely.