- Sanitize filenames in cache_document_from_bytes to prevent path traversal (strip directory components, null bytes, resolve check)
- Reject documents with None file_size instead of silently allowing download
- Cap text file injection at 100 KB to prevent oversized prompt payloads
- Sanitize display_name in run.py context notes to block prompt injection via filenames
- Add 35 unit tests covering document cache utilities and Telegram document handling
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>