fix(hooks): complete stale-hooks false-positive fix — stamp .sh version headers + fix detector regex (#2224)

* fix(hooks): stamp gsd-hook-version in .sh hooks and fix stale detection regex (#2136, #2206)

Three-part fix for the persistent "⚠ stale hooks — run /gsd-update" false
positive that appeared on every session after a fresh install.

Root cause: the stale-hook detector (gsd-check-update.js) could only match
the JS comment syntax // in its version regex — never the bash # syntax used
in .sh hooks. And the bash hooks had no version header at all, so they always
landed in the "unknown / stale" branch regardless.

Neither partial fix (PR #2207 regex only, PR #2215 install stamping only) was
sufficient alone:
  - Regex fix without install stamping: hooks install with literal
    "{{GSD_VERSION}}", the {{-guard silently skips them, bash hook staleness
    permanently undetectable after future updates.
  - Install stamping without regex fix: hooks are stamped correctly with
    "# gsd-hook-version: 1.36.0" but the detector's // regex can't read it;
    still falls to the unknown/stale branch on every session.

Fix:
  1. Add "# gsd-hook-version: {{GSD_VERSION}}" header to
     gsd-phase-boundary.sh, gsd-session-state.sh, gsd-validate-commit.sh
  2. Extend install.js (both bundled and Codex paths) to substitute
     {{GSD_VERSION}} in .sh files at install time (same as .js hooks)
  3. Extend gsd-check-update.js versionMatch regex to handle bash "#"
     comment syntax: /(?:\/\/|#) gsd-hook-version:\s*(.+)/

Tests: 11 new assertions across 5 describe blocks covering all three fix
parts independently plus an E2E install+detect round-trip. 3885/3885 pass.

Approach credit: PR #2207 (j2h4u / Maxim Brashenko) for the regex fix;
PR #2215 (nitsan2dots) for the install.js substitution approach.

Closes #2136, #2206, #2209, #2210, #2212

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* refactor(hooks): extract check-update worker to dedicated file, eliminating template-literal regex escaping

Move stale-hook detection logic from inline `node -e '<template literal>'` subprocess
to a standalone gsd-check-update-worker.js. Benefits:
- Regex is plain JS with no double-escaping (root cause of the (?:\\/\\/|#) confusion)
- Worker is independently testable and can be read directly by tests
- Uses execFileSync (array args) to satisfy security hook that blocks execSync
- MANAGED_HOOKS now includes gsd-check-update-worker.js itself

Update tests to read worker file instead of main hook for regex/configDir assertions.
All 3886 tests pass.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/managed-hooks.test.cjs

@@ -18,7 +18,9 @@ const fs = require('fs');
 const path = require('path');
 
 const HOOKS_DIR = path.join(__dirname, '..', 'hooks');
-const CHECK_UPDATE_FILE = path.join(HOOKS_DIR, 'gsd-check-update.js');
+// MANAGED_HOOKS now lives in the worker script (extracted from inline -e code
+// to avoid template-literal regex-escaping concerns). The test reads the worker.
+const MANAGED_HOOKS_FILE = path.join(HOOKS_DIR, 'gsd-check-update-worker.js');
 
 describe('bug #2136: MANAGED_HOOKS must include all shipped hook files', () => {
   let src;
@@ -26,12 +28,12 @@ describe('bug #2136: MANAGED_HOOKS must include all shipped hook files', () => {
   let shippedHooks;
 
   // Read once — all tests share the same source snapshot
-  src = fs.readFileSync(CHECK_UPDATE_FILE, 'utf-8');
+  src = fs.readFileSync(MANAGED_HOOKS_FILE, 'utf-8');
 
   // Extract the MANAGED_HOOKS array entries from the source
   // The array is defined as a multi-line array literal of quoted strings
   const match = src.match(/const MANAGED_HOOKS\s*=\s*\[([\s\S]*?)\]/);
-  assert.ok(match, 'MANAGED_HOOKS array not found in gsd-check-update.js');
+  assert.ok(match, 'MANAGED_HOOKS array not found in gsd-check-update-worker.js');
 
   managedHooks = match[1]
     .split('\n')
@@ -47,7 +49,7 @@ describe('bug #2136: MANAGED_HOOKS must include all shipped hook files', () => {
     for (const hookFile of jsHooks) {
       assert.ok(
         managedHooks.includes(hookFile),
-        `${hookFile} is shipped in hooks/ but missing from MANAGED_HOOKS in gsd-check-update.js`
+        `${hookFile} is shipped in hooks/ but missing from MANAGED_HOOKS in gsd-check-update-worker.js`
       );
     }
   });
@@ -57,7 +59,7 @@ describe('bug #2136: MANAGED_HOOKS must include all shipped hook files', () => {
     for (const hookFile of shHooks) {
       assert.ok(
         managedHooks.includes(hookFile),
-        `${hookFile} is shipped in hooks/ but missing from MANAGED_HOOKS in gsd-check-update.js`
+        `${hookFile} is shipped in hooks/ but missing from MANAGED_HOOKS in gsd-check-update-worker.js`
       );
     }
   });