enh(#3811): add hooks.commit_types config surface to gsd-validate-commit (#4340)

* enh(#3811): add hooks.commit_types config surface to gsd-validate-commit

Extends the opt-in Conventional Commits hook with a hooks.commit_types
config array that adds project-specific types to the 10 built-ins
without replacing them. Configured values pass a safe-token filter
before reaching the compiled regex, so a config entry can never alter
the pattern's structure. The regex alternation, the human-readable
error text, and a new typed valid_types JSON field all derive from one
list instead of the two hand-synced copies this replaces.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* chore(#3811): backfill changeset PR number

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

---------

Co-authored-by: sim <sim@local>
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>

docs/features/community-hooks-opt-in.md

@@ -18,3 +18,4 @@ group: v1.32 Features
 | Setting | Type | Default | Description |
 |---------|------|---------|-------------|
 | `hooks.community` | boolean | `false` | Enable optional community hooks for commit validation, session state, and phase boundaries |
+| `hooks.commit_types` | array of strings | `[]` | Extra Conventional Commits types `gsd-validate-commit.sh` accepts, in addition to the built-in `feat, fix, docs, style, refactor, perf, test, build, ci, chore` — never replaces them. Each entry must match `^[a-z][a-z0-9-]*$` (lowercase letters, digits, hyphens); non-conforming or non-string entries are dropped. Example: `{ "hooks": { "community": true, "commit_types": ["enhance", "enh", "revert"] } }`. |