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/batch-agent/README.md

@@ -0,0 +1,20 @@
+# Batch Agent Service
+
+Owns: agent_runner, journey builder, filesystem_agent, integrations (Gmail, MS Graph).
+
+## Tables owned
+- `local_agent_configs`
+- `cloud_agent_configs`
+- `agent_run_logs`
+
+## Endpoints
+- `GET /agents/catalog`
+- `POST /agents/can-create`
+- `POST /agents/trigger`
+- `GET /agents/{id}/history`
+
+## Redis channels
+- Subscribe: `batch:request:{user_id}`
+- Publish: `ws:out:{user_id}` (journey replies + tool calls)
+- BRPOP: `tool:result:{call_id}` (30s timeout)
+- SET+EX: `journey:{user_id}` (session state, TTL 1800s)