feat: add WS Gateway and Chat Service (Step 2)

WS Gateway:
- WebSocket lifecycle handler with RS256 JWT auth
- Redis bridge: device registry, frame publishing, tool_result routing
- Inbound routing: tool_result→LPUSH, home/floating→chat pub/sub
- Outbound: subscribes to ws:out:{user_id}, forwards to Electron
- Single-worker Dockerfile (long-lived WS connections)

Chat Service:
- Redis consumer: subscribes to chat:request:* pattern
- Redis-based ws_context: tool_call→publish, BRPOP tool_result (30s timeout)
- deep_agent: single-agent runner with home/floating/stream variants
- memory_middleware: core/associative/episodic/proactive memory with Fernet
- Domain agents: task (8 tools), note (5), project (6), timeline (4)
- LLM factory via LiteLLM (100+ providers)
- Output formatter (StreamFormatter)
- POST /chat REST fallback with Traefik header auth
- Multi-worker Dockerfile with 120s timeout for LLM calls

services/ws-gateway/requirements.txt

@@ -0,0 +1,8 @@
+fastapi>=0.115.0
+uvicorn[standard]>=0.34.0
+gunicorn>=22.0.0
+pydantic>=2.10.0
+pydantic-settings>=2.7.0
+python-jose[cryptography]>=3.3.0
+redis>=5.0.0
+websockets>=14.0