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()

.gitignore

@@ -28,6 +28,7 @@ env/
 # IDE
 .vscode/
 .idea/
+.ruff_cache
 *.swp
 *.swo
 *~
@@ -37,6 +38,17 @@ env/
 
 # Memory and state files
 memory.json
+memory_data/
+
+# Coverage reports
+.coverage
+.coverage.*
+htmlcov/
+coverage.xml
+*.cover
+
+# Pytest cache
+.pytest_cache/
 
 # OS
 .DS_Store
@@ -44,3 +56,6 @@ Thumbs.db
 
 # Secrets
 .env
+
+# Backup files
+*.backup