fix(#3010): post-install message and docs use /gsd-update --reapply (#3012)

* fix(#3010): post-install message and docs use /gsd-update --reapply

PR #2824 consolidated 86 skills into ~58, removing the standalone
/gsd-reapply-patches command and folding it into a flag on /gsd-update
(/gsd-update --reapply). The 1.39.1 hotfix (#2954) updated help.md
but missed three other surfaces that still recommended the dead form:

1. bin/install.js reportLocalPatches() — runtime emitter shown after
   every install with backed-up patches. All branches updated:
   - claude/opencode/kilo/copilot: /gsd-update --reapply
   - gemini: /gsd:update --reapply
   - codex: $gsd-update --reapply
   - cursor: gsd-update --reapply (mention the skill name)

2. get-shit-done/workflows/update.md — Step 4 prose and the
   check_local_patches block both referenced /gsd-reapply-patches.
   Replaced with /gsd-update --reapply (with backticks around the
   command per CR feedback for copy/paste UX).

3. Localized docs (en/ja-JP/ko-KR/zh-CN) — 14 files across
   ARCHITECTURE.md / COMMANDS.md / FEATURES.md / INVENTORY.md /
   USER-GUIDE.md / manual-update.md still listed the removed command.

Tests:
- bug-3010-reapply-patches-references.test.cjs (4 tests): scans
  bin/install.js's reportLocalPatches body, every workflow file, and
  every doc (excluding CHANGELOG history and help.md's deprecation
  notice) for the removed command form, and verifies each runtime
  branch emits the consolidated form via captured console output.
- tests/copilot-install.test.cjs:1081-1115 — stale assertions that
  hard-coded the removed string updated to assert /gsd-update --reapply.

Verification: 115/115 pass across both files.

Co-authored-by: Patrick Clery <patrick@patrickclery.com>
Closes #3010

* test(#3010): broaden dead-command scan + tighten runtime exact-match

CodeRabbit follow-up findings on #3012:

1. Workflow + docs scans only matched "/gsd-reapply-patches", missing
   the gemini ("/gsd:reapply-patches") and codex ("$gsd-reapply-patches")
   spellings. A regression that re-introduced either form in localized
   docs would have passed silently. Extracted a DEAD_COMMAND_PATTERNS
   array + findDeadCommands() helper used by both scans, so all three
   removed forms are checked uniformly. Match output also reports which
   spellings hit, for faster diagnosis.

2. reportLocalPatches runtime test asserted output.includes('update --reapply'),
   which is too loose — a malformed prefix like '/gsd:update --reapply' on
   the claude branch would have passed. Replaced with an exact
   {runtime → expected token} map covering all 7 branches:
     claude/opencode/kilo/copilot → /gsd-update --reapply
     gemini → /gsd:update --reapply
     codex → $gsd-update --reapply
     cursor → gsd-update --reapply
   Negative assertion also runs DEAD_COMMAND_PATTERNS against output for
   every runtime, so dead forms can't slip in regardless of branch.

Verification: 4/4 pass on bug-3010-reapply-patches-references.test.cjs.

* test(#3010): add prefix-absence guard for cursor runtime (CR follow-up)

CodeRabbit (Minor): the cursor expected token "gsd-update --reapply" is
a substring of every prefixed form ("/gsd-update --reapply" for claude/
opencode/kilo/copilot, "\$gsd-update --reapply" for codex). The positive
output.includes(expectedToken) check therefore can't distinguish correct
cursor output from a regression where the installer emits a prefixed
form for cursor — both pass the substring check.

Add an explicit prefix-absence assertion for cursor that fails if any
of /, \$, or : appears immediately before "gsd-update --reapply" in
output. The gemini form ("/gsd:update --reapply") doesn't share the
substring (gsd:update vs gsd-update) so it's already caught by the
positive includes failing on cursor's expected bare token.

Verification: 4/4 pass.

---------

Co-authored-by: Patrick Clery <patrick@patrickclery.com>

docs/FEATURES.md

@@ -902,7 +902,7 @@ continues. Drift detection cannot fail verification.
 - REQ-UPDATE-02: System MUST display changelog for new version before updating
 - REQ-UPDATE-03: System MUST be runtime-aware and target the correct directory
 - REQ-UPDATE-04: System MUST back up locally modified files to `gsd-local-patches/`
-- REQ-UPDATE-05: `/gsd-reapply-patches` MUST restore local modifications after update
+- REQ-UPDATE-05: `/gsd-update --reapply` MUST restore local modifications after update
 
 ---
 
@@ -2255,7 +2255,7 @@ Test suite that scans all agent, workflow, and command files for embedded inject
 
 ### 103. Post-Merge Hunk Verification
 
-**Command:** `/gsd-reapply-patches`
+**Command:** `/gsd-update --reapply`
 
 **Purpose:** After applying local patches post-update, verify that all hunks were actually applied by comparing the expected patch content against the live filesystem. Surface any dropped or partial hunks immediately rather than silently accepting incomplete merges.