fix(#941): track managed-hooks-registry.cjs in file manifest (#953)

* test(#941): regression test for managed-hooks-registry.cjs manifest omission

Adds bug-941-managed-hooks-registry-manifest.test.cjs which verifies:
- managed-hooks-registry.cjs appears in gsd-file-manifest.json after install
- manifest covers the full HOOKS_TO_COPY set (forward-proof)
- detect-custom-files reports 0 custom files after a clean install
- manifest hook keys use forward slashes (cross-platform)

All four assertions fail before the fix, confirming the bug is reproducible.

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

* fix(#941): track managed-hooks-registry.cjs in file manifest

The writeManifest() hooks loop in bin/install.js filtered hook filenames
with `file.startsWith('gsd-') && (file.endsWith('.js') || file.endsWith('.sh'))`.
managed-hooks-registry.cjs fails both predicates (wrong prefix, .cjs extension),
so it was never recorded in gsd-file-manifest.json even though it is shipped to
users as part of HOOKS_TO_COPY.

detect-custom-files scans the installed hooks/ dir and reports any file with no
manifest entry as a custom file, producing a perpetual false-positive
"Found 1 custom file(s)" warning on every /gsd-update for all users.

Fix: import HOOKS_TO_COPY from scripts/build-hooks.js and drive the manifest
hooks loop from that set (as a Set for O(1) lookup), so the manifest set is
structurally identical to the build set. Any future hook of any prefix or
extension added to HOOKS_TO_COPY is automatically covered. The new regression
test asserts full HOOKS_TO_COPY coverage and zero detect-custom-files
false-positives after a clean install.

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

* chore(#941): add changeset for managed-hooks-registry.cjs manifest fix

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

* test(#941): assert manifest hash matches installed hook contents (adversarial review)

Strengthen the regression test to not only verify that the manifest KEY
`hooks/managed-hooks-registry.cjs` is present after install, but also that
the stored hash equals the SHA256 of the actual installed file bytes — the
same algorithm used by the installer's fileHash() function.  A future
refactor that records the right key from the wrong path or content would
now fail this assertion immediately.

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

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

bin/install.js

@@ -38,6 +38,12 @@ const {
   readBaseRefFromSettings,
 } = require('../gsd-core/bin/lib/worktree-base-ref.cjs');
 const { resolveRuntimeConfigIntent } = require('../gsd-core/bin/lib/runtime-config-adapter-registry.cjs');
+// Canonical set of hook files shipped to users. Imported here so writeManifest()
+// records exactly the same set that build-hooks.js copies to hooks/dist/, making
+// the manifest and the installed hooks/ dir structurally identical. Avoids the
+// prefix/extension-regex approach that missed managed-hooks-registry.cjs (#941).
+const { HOOKS_TO_COPY: _HOOKS_TO_COPY } = require('../scripts/build-hooks.js');
+const INSTALLED_HOOK_FILES = new Set(_HOOKS_TO_COPY);
 
 /**
  * Runtimes that register hyphen-form `name:` per #2808 AND copy agent bodies
@@ -9612,9 +9618,17 @@ function writeManifest(configDir, runtime = 'claude', options = {}) {
   if (!isCodex && !isCopilot && !isCline && !isKimi) {
     const hooksDir = path.join(configDir, 'hooks');
     if (fs.existsSync(hooksDir)) {
-      for (const file of fs.readdirSync(hooksDir)) {
-        if (file.startsWith('gsd-') && (file.endsWith('.js') || file.endsWith('.sh'))) {
-          manifest.files['hooks/' + file] = fileHash(path.join(hooksDir, file));
+      // Drive from INSTALLED_HOOK_FILES (the canonical HOOKS_TO_COPY set from
+      // scripts/build-hooks.js) rather than a prefix/extension regex, so the
+      // manifest set is structurally identical to the build set. The old regex
+      // `file.startsWith('gsd-') && (file.endsWith('.js') || file.endsWith('.sh'))`
+      // missed managed-hooks-registry.cjs (wrong prefix, .cjs extension), causing
+      // detect-custom-files to flag it as a perpetual false-positive custom file
+      // on every /gsd-update. See #941.
+      for (const hook of INSTALLED_HOOK_FILES) {
+        const hookPath = path.join(hooksDir, hook);
+        if (fs.existsSync(hookPath)) {
+          manifest.files['hooks/' + hook] = fileHash(hookPath);
         }
       }
       // Track hooks/lib/ helpers so saveLocalPatches() can back up user edits