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/dto.py

@@ -1,17 +1,18 @@
 """Knaben Data Transfer Objects."""
+
 from dataclasses import dataclass
-from typing import Optional
 
 
 @dataclass
 class TorrentResult:
     """Represents a torrent search result from Knaben."""
+
     title: str
     size: str
     seeders: int
     leechers: int
     magnet: str
-    info_hash: Optional[str] = None
-    tracker: Optional[str] = None
-    upload_date: Optional[str] = None
-    category: Optional[str] = None
+    info_hash: str | None = None
+    tracker: str | None = None
+    upload_date: str | None = None
+    category: str | None = None