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/persistence/__init__.py

@@ -1 +1,25 @@
 """Persistence layer - Data storage implementations."""
+
+from .context import (
+    get_memory,
+    has_memory,
+    init_memory,
+    set_memory,
+)
+from .memory import (
+    EpisodicMemory,
+    LongTermMemory,
+    Memory,
+    ShortTermMemory,
+)
+
+__all__ = [
+    "Memory",
+    "LongTermMemory",
+    "ShortTermMemory",
+    "EpisodicMemory",
+    "init_memory",
+    "set_memory",
+    "get_memory",
+    "has_memory",
+]