fix-reasonlisted

# Reason (三步法 Step 2) After observing the symptom: 1. Trace backwards from the symptom to possible causes 2. Check the most likely cause first (80/20 rule) 3. Read the relevant code 4. If multiple possible causes, test each one systematically 5. Confirm root cause before attempting fix Common root causes: - Typo in variable name or URL - Missing dependency or import - Wrong file path - Database not connected - Port already in use - Permission denied - API key expired or wrong DO NOT guess and patch. Find the REAL cause.