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/chat/app/routes.py

@@ -0,0 +1,37 @@
+"""Chat REST route — POST /chat fallback when WS is unavailable."""
+
+from __future__ import annotations
+
+from fastapi import APIRouter, Request
+from fastapi.responses import JSONResponse
+
+from shared.schemas import ChatRequest
+
+from app.deep_agent import run_home
+from app.ws_context import clear_current_user, set_current_user
+
+router = APIRouter(prefix="/chat", tags=["chat"])
+
+
+@router.post("")
+async def chat(body: ChatRequest, request: Request) -> JSONResponse:
+    """REST fallback for home chat.
+
+    In the microservices setup, Traefik ForwardAuth has already validated
+    the JWT and injected X-User-Id / X-User-Email / X-User-Tier headers.
+    """
+    user_id = request.headers.get("X-User-Id", "")
+    if not user_id:
+        return JSONResponse(status_code=401, content={"detail": "Missing X-User-Id header"})
+
+    set_current_user(user_id)
+    try:
+        response = await run_home(
+            user_id=user_id,
+            message=body.message,
+            context=body.context.model_dump(),
+        )
+    finally:
+        clear_current_user()
+
+    return JSONResponse(content={"response": response})