feat(#777): register Cursor-native hooks (.cursor/hooks.json) for session-start/post-tool parity (#831)

* feat(#777): register Cursor-native hooks (.cursor/hooks.json) for session-start/post-tool parity

- Add gsd-cursor-session-start.js: injects STATE.md presence reminder (or
  new-project nudge) into Cursor sessions via the sessionStart hook event
- Add gsd-cursor-post-tool.js: emits an additional_context nudge when
  write-class tool calls touch .planning/ files (postToolUse hook event)
- Add 'cursor-hooks-json' installSurface to runtime-config-adapter-registry;
  writeCursorHooksJson/reconcileCursorHooksJson write the canonical
  { version: 1, hooks: { sessionStart, postToolUse } } JSON shape with
  idempotent reconciliation that preserves user-owned hook entries
- Hook scripts are copied with /gsd:→gsd- rewrite so installed files
  contain no colon-form slash-command refs (bug-376 invariant)
- 20 new tests in tests/cursor-hooks.test.cjs cover all reconciler paths,
  entry helpers, removal, runtime adapter surface, and hook script behavior
- Update CONTEXT.md, ARCHITECTURE.md, installer-migrations.md, and
  000-first-time-baseline.cts to include Cursor hooks.json surface

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* fix(#777): build hooks/dist on demand in bug-376 test for scoped/windows CI

hooks/dist is gitignored and only produced by `npm run build:hooks`.
The CI scoped (ubuntu-latest/node-22) and windows (windows-latest/node-24)
test jobs do NOT run build:hooks before executing tests, so bug-376's
prerequisite suite was failing with "hooks/dist not found" on both legs.

Add ensureHooksDist() helper (mirrors bug-3357 pattern) that builds
hooks/dist on demand in the before() hooks of prerequisite and Suite 3.
Also add ensureHooksDist() call to Suite 3's before() so the snapshot
step is also hermetic.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

scripts/build-hooks.js

@@ -30,6 +30,9 @@ const HOOKS_TO_COPY = [
   // so require('./managed-hooks-registry.cjs') resolves in the installed hooks/ dir.
   'managed-hooks-registry.cjs',
   'gsd-context-monitor.js',
+  // Cursor lifecycle hooks (issue #777): sessionStart context injection + postToolUse monitor
+  'gsd-cursor-session-start.js',
+  'gsd-cursor-post-tool.js',
   'gsd-prompt-guard.js',
   'gsd-read-guard.js',
   'gsd-read-injection-scanner.js',