🤖 chore: finalize Git hooks implementation and documentation

- Complete Git hooks setup with staged-only formatting
- Add comprehensive documentation and ADR
- Fix BDD step template syntax error
- Update commit_message skill with hooks integration
- Verify all hooks work correctly

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

.vibe/skills/commit_message/assets/git-hooks/README.md

@@ -10,7 +10,7 @@ This directory contains Git hooks for the DanceLessonsCoach project.
 - **Features**:
   - Runs `go mod tidy` to clean up dependencies
   - Automatically adds modified `go.mod` and `go.sum` to commit
-  - Runs `go fmt` on all Go files (excluding vendor and .git directories)
+  - Runs `go fmt` on staged Go files only
   - Automatically adds formatted files to commit
   - Only runs if in a Go project (checks for `go.mod`)