PURPOSE: Generate semantic summaries and search keywords for code files
TASK:
- For each code block, generate a concise summary (1-2 sentences)
- Extract 5-10 relevant search keywords
- Identify the functional purpose/category
MODE: analysis
EXPECTED: JSON format output

=== CODE BLOCKS ===
[FILE: auth.py]
```python
def auth(): pass
```

=== OUTPUT FORMAT ===
Return ONLY valid JSON (no markdown, no explanation):
{
  "files": {
    "<file_path>": {
      "summary": "Brief description of what this code does",
      "keywords": ["keyword1", "keyword2", ...],
      "purpose": "category like: auth, api, util, ui, data, config, test"
    }
  }
}