feat: microservices scaffold + Auth Service (Step 1)

- Add shared/ module: config, db, models, schemas, redis utilities
- Add Auth Service (services/auth/): register, login, refresh, me,
  ForwardAuth /verify endpoint for Traefik
- Add Traefik config: ACME/Cloudflare DNS-01, dynamic routing,
  ForwardAuth middleware, sticky sessions for WS Gateway
- Add service scaffolds: ws-gateway, chat, batch-agent, billing (READMEs)
- Add redis>=5.0.0 to requirements.txt
- Monolith app/ is untouched — strangler fig migration

services/chat/README.md

@@ -0,0 +1,21 @@
+# Chat Service
+
+Owns: deep_agent (home + floating chat), memory middleware, domain agents
+(task, note, project, timeline), LLM orchestration.
+
+## Tables owned
+- `memory_core`
+- `memory_associative`
+- `memory_episodic`
+- `memory_proactive`
+
+## Tables read (cross-service)
+- `users` (for encryption_key — memory decryption)
+
+## Endpoints
+- `POST /chat` (REST fallback)
+
+## Redis channels
+- Subscribe: `chat:request:{user_id}`
+- Publish: `ws:out:{user_id}` (stream frames + tool calls)
+- BRPOP: `tool:result:{call_id}` (30s timeout)