feat(infra): p6 hardening - observability and deploy compose

- 5 NestJS services add /metrics endpoint via app.getHttpAdapter()
- prometheus.yml scales to 8 services with rule_files and alertmanager
- monitoring compose replaces blackbox with Loki+Promtail
- Grafana datasource adds Loki
- docker-compose.deploy.yml scales to 11 services
- deploy.env.example completes Neo4j/ES/ClickHouse/LLM vars
- teacher-bff adds health.controller
- CI removes continue-on-error on lint step
- teacher-portal lint script changed to eslint src

.github/workflows/ci.yml

@@ -45,14 +45,13 @@ jobs:
 
       - name: Lint
         run: pnpm -r run lint
-        continue-on-error: true # P1: ESLint 9 flat config 迁移未完成
 
       - name: Typecheck
         run: pnpm -r run typecheck
 
       - name: Test
         run: pnpm -r run test
-        continue-on-error: true # P1: 部分服务无 test 脚本
+        continue-on-error: true # P6: 部分服务无 test 脚本，待补全
 
       - name: Build
         run: pnpm -r run build