fix: address fourth round of PR review comments

- Validate extension_id against ^[a-z0-9-]+$ in _locate_bundled_extension
  to prevent path traversal (security fix)
- Move defaults under config.defaults in extension.yml to match
  ConfigManager._get_extension_defaults() schema
- Ship git-config.yml in extension directory so it's copied during
  install (provides.config template isn't materialized by ExtensionManager)
- Condition handling in hook templates: intentionally matches existing
  pattern from specify/plan/tasks/implement templates (not a new issue)

Author: mnriem

extensions/git/extension.yml

@@ -134,6 +134,7 @@ tags:
   - "branching"
   - "workflow"
 
-defaults:
-  branch_numbering: sequential
-  init_commit_message: "[Spec Kit] Initial commit"
+config:
+  defaults:
+    branch_numbering: sequential
+    init_commit_message: "[Spec Kit] Initial commit"

extensions/git/git-config.yml

@@ -0,0 +1,62 @@
+# Git Branching Workflow Extension Configuration
+# Copied to .specify/extensions/git/git-config.yml on install
+
+# Branch numbering strategy: "sequential" (001, 002, ...) or "timestamp" (YYYYMMDD-HHMMSS)
+branch_numbering: sequential
+
+# Commit message used by `git commit` during repository initialization
+init_commit_message: "[Spec Kit] Initial commit"
+
+# Auto-commit before/after core commands.
+# Set "default" to enable for all commands, then override per-command.
+# Each key can be true/false. Message is customizable per-command.
+auto_commit:
+  default: false
+  before_clarify:
+    enabled: false
+    message: "[Spec Kit] Save progress before clarification"
+  before_plan:
+    enabled: false
+    message: "[Spec Kit] Save progress before planning"
+  before_tasks:
+    enabled: false
+    message: "[Spec Kit] Save progress before task generation"
+  before_implement:
+    enabled: false
+    message: "[Spec Kit] Save progress before implementation"
+  before_checklist:
+    enabled: false
+    message: "[Spec Kit] Save progress before checklist"
+  before_analyze:
+    enabled: false
+    message: "[Spec Kit] Save progress before analysis"
+  before_taskstoissues:
+    enabled: false
+    message: "[Spec Kit] Save progress before issue sync"
+  after_constitution:
+    enabled: false
+    message: "[Spec Kit] Add project constitution"
+  after_specify:
+    enabled: false
+    message: "[Spec Kit] Add specification"
+  after_clarify:
+    enabled: false
+    message: "[Spec Kit] Clarify specification"
+  after_plan:
+    enabled: false
+    message: "[Spec Kit] Add implementation plan"
+  after_tasks:
+    enabled: false
+    message: "[Spec Kit] Add tasks"
+  after_implement:
+    enabled: false
+    message: "[Spec Kit] Implementation progress"
+  after_checklist:
+    enabled: false
+    message: "[Spec Kit] Add checklist"
+  after_analyze:
+    enabled: false
+    message: "[Spec Kit] Add analysis report"
+  after_taskstoissues:
+    enabled: false
+    message: "[Spec Kit] Sync tasks to issues"

src/specify_cli/__init__.py

@@ -610,6 +610,10 @@ def _locate_bundled_extension(extension_id: str) -> Path | None:
     Checks the wheel's core_pack first, then falls back to the
     source-checkout ``extensions/<id>/`` directory.
     """
+    import re as _re
+    if not _re.match(r'^[a-z0-9-]+$', extension_id):
+        return None
+
     core = _locate_core_pack()
     if core is not None:
         candidate = core / "extensions" / extension_id