feat!: migrate to OpenAI native tool calls and fix circular deps (#fuck-gemini)

- Fix circular dependencies in agent/tools
- Migrate from custom JSON to OpenAI tool calls format
- Add async streaming (step_stream, complete_stream)
- Simplify prompt system and remove token counting
- Add 5 new API endpoints (/health, /v1/models, /api/memory/*)
- Add 3 new tools (get_torrent_by_index, add_torrent_by_index, set_language)
- Fix all 500 tests and add coverage config (80% threshold)
- Add comprehensive docs (README, pytest guide)

BREAKING: LLM interface changed, memory injection via get_memory()

infrastructure/api/knaben/exceptions.py

@@ -3,19 +3,23 @@
 
 class KnabenError(Exception):
     """Base exception for Knaben-related errors."""
+
     pass
 
 
 class KnabenConfigurationError(KnabenError):
     """Raised when Knaben API is not properly configured."""
+
     pass
 
 
 class KnabenAPIError(KnabenError):
     """Raised when Knaben API returns an error."""
+
     pass
 
 
 class KnabenNotFoundError(KnabenError):
     """Raised when no torrents are found."""
+
     pass