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()

domain/movies/exceptions.py

@@ -1,17 +1,21 @@
 """Movie domain exceptions."""
+
 from ..shared.exceptions import DomainException, NotFoundError
 
 
 class MovieNotFound(NotFoundError):
     """Raised when a movie is not found."""
+
     pass
 
 
 class InvalidMovieData(DomainException):
     """Raised when movie data is invalid."""
+
     pass
 
 
 class MovieAlreadyExists(DomainException):
     """Raised when trying to add a movie that already exists."""
+
     pass