fix: improve git hook JSON escaping

Fixed post-commit hook to properly escape JSON payloads using python.
Previous implementation was vulnerable to breaking on commit messages
with special characters (quotes, newlines, etc.).

CHANGES:
- Use python json.dumps() for proper JSON escaping
- Prevents 422 validation errors from coordination API
- Handles multi-line commit messages correctly

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.claude/hooks/post-commit.template

@@ -38,15 +38,29 @@ if [[ -n "$SPEC_FILES" ]]; then
     # Send dev-alerts message
     SESSION_ID=$(hostname)/claude-main
 
+    # Build JSON payload with proper escaping
+    JSON_PAYLOAD=$(python3 -c "import json; print(json.dumps({
+        'from_session': '$SESSION_ID',
+        'to_session': 'dev-alerts',
+        'project_key': '$PROJECT',
+        'subject': '$PROJECT_NAME Feature Spec: $SPEC_NUM $SPEC_NAME',
+        'body': '''New $PROJECT_NAME feature specification created.
+
+$SPEC_NUM: $SPEC_NAME
+Priority: $PRIORITY | Effort: $EFFORT
+
+OVERVIEW:
+$OVERVIEW
+
+Commit: $COMMIT_HASH on $BRANCH
+Author: $AUTHOR
+
+🤖 Auto-generated via post-commit hook'''
+    }))")
+
     curl -s -X POST http://172.16.3.30:8001/api/coord/messages \
       -H "Content-Type: application/json" \
-      -d "{
-        \"from_session\": \"$SESSION_ID\",
-        \"to_session\": \"dev-alerts\",
-        \"project_key\": \"$PROJECT\",
-        \"subject\": \"$PROJECT_NAME Feature Spec: $SPEC_NUM $SPEC_NAME\",
-        \"body\": \"New $PROJECT_NAME feature specification created.\\n\\n$SPEC_NUM: $SPEC_NAME\\nPriority: $PRIORITY | Effort: $EFFORT\\n\\nOVERVIEW:\\n$OVERVIEW\\n\\nCommit: $COMMIT_HASH on $BRANCH\\nAuthor: $AUTHOR\\n\\n🤖 Auto-generated via post-commit hook\"
-      }" > /dev/null 2>&1
+      -d "$JSON_PAYLOAD" > /dev/null 2>&1
 fi
 
 # Detect build/push events (commit message contains 'spec:', 'feat:', 'fix:', etc.)
@@ -59,15 +73,29 @@ if echo "$COMMIT_MSG" | grep -qE '^(spec|feat|fix|chore|docs|build):'; then
 
         SESSION_ID=$(hostname)/claude-main
 
+        # Build JSON payload with proper escaping
+        JSON_PAYLOAD=$(python3 -c "import json; print(json.dumps({
+            'from_session': '$SESSION_ID',
+            'to_session': 'dev-alerts',
+            'project_key': '$PROJECT',
+            'subject': '$PROJECT_NAME Build: $COMMIT_TYPE on main',
+            'body': '''$PROJECT_NAME main branch updated.
+
+COMMIT: $COMMIT_HASH
+TYPE: $COMMIT_TYPE
+FILES CHANGED: $FILES_CHANGED
+BRANCH: $BRANCH
+AUTHOR: $AUTHOR
+
+MESSAGE:
+$COMMIT_MSG
+
+🔨 Auto-generated via post-commit hook'''
+        }))")
+
         curl -s -X POST http://172.16.3.30:8001/api/coord/messages \
           -H "Content-Type: application/json" \
-          -d "{
-            \"from_session\": \"$SESSION_ID\",
-            \"to_session\": \"dev-alerts\",
-            \"project_key\": \"$PROJECT\",
-            \"subject\": \"$PROJECT_NAME Build: $COMMIT_TYPE on main\",
-            \"body\": \"$PROJECT_NAME main branch updated.\\n\\nCOMMIT: $COMMIT_HASH\\nTYPE: $COMMIT_TYPE\\nFILES CHANGED: $FILES_CHANGED\\nBRANCH: $BRANCH\\nAUTHOR: $AUTHOR\\n\\nMESSAGE:\\n$COMMIT_MSG\\n\\n🔨 Auto-generated via post-commit hook\"
-          }" > /dev/null 2>&1
+          -d "$JSON_PAYLOAD" > /dev/null 2>&1
     fi
 fi