fix(3610): unblock fresh Codex install when leftover bundled hooks present

`npx get-shit-done-cc@latest --codex` aborted with
"installer migration blocked pending user choice" listing 12 hooks/gsd-*
files. Those files are part of the GSD npm distribution
(hooks/gsd-prompt-guard.js, hooks/gsd-context-monitor.js, etc.), not
user-owned content, so asking the user to choose between keep/remove for
them was a UX bug, not a real choice. The installer is about to write
the fresh bundled versions in their place.

Root cause: `classifyPromptUserAction` in
get-shit-done/bin/lib/installer-migration-report.cjs knew two
unambiguous categories (`stale-sdk-build-artifact`, `user-facing-skill`)
but had no rule for the bundled GSD hooks. The first-time-baseline scan
classified them as `stale-gsd-looking` prompt-user blockers, and
`assertInstallerMigrationsUnblocked` threw.

A second gate compounded the bug: the safe-default resolver in
bin/install.js was wrapped in `if (!_migrationIsTty)`, so even with a
correct classification rule, TTY runs (every `npx get-shit-done-cc`
invocation) skipped the resolver and went straight to the hard throw.

Fix:
1) Add `hooks/gsd-<name>.(js|sh|cjs|mjs)` to `classifyPromptUserAction`
   as `bundled-gsd-hook` → `remove`. The regex is anchored at the
   top-level `hooks/` directory so nested paths like
   `hooks/gsd-helpers/index.js` (or any user-owned helper directory) do
   NOT auto-classify.
2) Remove the `!_migrationIsTty` gate from the resolver call in
   bin/install.js. The classifier-based path is unambiguous and must
   apply regardless of TTY; the env-override branch
   (GSD_INSTALLER_MIGRATION_RESOLVE) still applies only when isTty=false
   inside the resolver, preserving the #3541 semantic.

Regression test added
(tests/bug-3610-installer-migration-bundled-hooks-classification.test.cjs):

- Positive: hooks/gsd-*.{js,sh} → category=bundled-gsd-hook, choice=remove.
- Counter-test: hooks/my-custom-hook.js → classifier returns null
  (user files are preserved).
- Boundary: hooks/gsd-helpers/index.js → classifier returns null
  (nested directories don't auto-classify).
- End-to-end: 12 reporter-exact bundled hooks + empty manifest →
  resolver clears every blocker, assertInstallerMigrationsUnblocked
  does not throw.

Test exercises the real installer-migration code path
(`runInstallerMigrations` + `resolveInstallerMigrationPromptsForNonTty`
+ `assertInstallerMigrationsUnblocked`) — no source-grep, no raw text
matching on outputs.

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

get-shit-done/bin/lib/installer-migration-report.cjs

@@ -115,6 +115,17 @@ function classifyPromptUserAction(action) {
   if (/^skills\/gsd-[^/]+\/SKILL\.md$/.test(relPath)) {
     return { category: 'user-facing-skill', choice: 'keep' };
   }
+  // #3610: bundled GSD hooks at hooks/gsd-<name>.<ext>. These are part of
+  // the npm distribution (`hooks/gsd-*.{js,sh,cjs,mjs}` shipped in the
+  // package), NOT user-owned files. When a first-time-baseline scan finds
+  // them on disk without manifest entries — the case for any upgrade from
+  // a pre-manifest-baseline release — the safe default is to remove them
+  // so the installer can write the fresh bundled versions in their place.
+  // Restricted to top-level files (`hooks/gsd-X.ext`) so nested user
+  // directories like `hooks/gsd-helpers/...` do NOT auto-classify.
+  if (/^hooks\/gsd-[^/]+\.(?:js|sh|cjs|mjs)$/.test(relPath)) {
+    return { category: 'bundled-gsd-hook', choice: 'remove' };
+  }
   return null;
 }