🤖 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/pre-commit

@@ -25,18 +25,18 @@ if git diff --cached --name-only | grep -qE '(go\.mod|go\.sum)'; then
     git add go.mod go.sum
 fi
 
-# Run go fmt on all Go files
-echo "Running go fmt..."
-GOFILES=$(find . -name '*.go' -not -path "./vendor/*" -not -path "./.git/*")
-if [ -n "$GOFILES" ]; then
-    gofmt -w $GOFILES
+# Run go fmt on staged Go files only
+echo "Running go fmt on staged files..."
+STAGED_GOFILES=$(git diff --cached --name-only --diff-filter=ACM | grep '\.go$')
+if [ -n "$STAGED_GOFILES" ]; then
+    gofmt -w $STAGED_GOFILES
     if [ $? -ne 0 ]; then
         echo "ERROR: go fmt failed"
         exit 1
     fi
     
     # Add formatted files to commit
-    git add $GOFILES
+    git add $STAGED_GOFILES
 fi
 
 echo "Pre-commit hooks completed successfully"