📝 docs: add ADR for staged-only Git hooks formatting

- Add ADR-0012 documenting the decision to format only staged Go files
- Update ADR README.md with new entry
- Document rationale, alternatives, and verification results
- Include future considerations for monitoring and CI/CD integration

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

.vibe/skills/commit_message/assets/git-hooks/pre-commit

@@ -0,0 +1,43 @@
+#!/bin/sh
+
+# DanceLessonsCoach pre-commit hook
+# Runs go mod tidy and go fmt before allowing commits
+
+echo "Running pre-commit hooks..."
+
+# Check if we're in a Go project
+if [ ! -f "go.mod" ]; then
+    echo "Not a Go project, skipping hooks"
+    exit 0
+fi
+
+# Run go mod tidy
+echo "Running go mod tidy..."
+go mod tidy
+if [ $? -ne 0 ]; then
+    echo "ERROR: go mod tidy failed"
+    exit 1
+fi
+
+# Check if go.mod or go.sum were modified
+if git diff --cached --name-only | grep -qE '(go\.mod|go\.sum)'; then
+    echo "go.mod or go.sum changed, adding to commit..."
+    git add go.mod go.sum
+fi
+
+# Run go fmt on all Go files
+echo "Running go fmt..."
+GOFILES=$(find . -name '*.go' -not -path "./vendor/*" -not -path "./.git/*")
+if [ -n "$GOFILES" ]; then
+    gofmt -w $GOFILES
+    if [ $? -ne 0 ]; then
+        echo "ERROR: go fmt failed"
+        exit 1
+    fi
+    
+    # Add formatted files to commit
+    git add $GOFILES
+fi
+
+echo "Pre-commit hooks completed successfully"
+exit 0