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

infra/promtail/config.yml

@@ -0,0 +1,28 @@
+server:
+  http_listen_port: 9080
+  grpc_listen_port: 0
+
+positions:
+  filename: /tmp/positions.yaml
+
+clients:
+  - url: http://loki:3100/loki/api/v1/push
+
+scrape_configs:
+  # 采集 Docker 容器日志
+  - job_name: docker
+    docker_sd_configs:
+      - host: unix:///var/run/docker.sock
+        refresh_interval: 5s
+    relabel_configs:
+      # 只采集带 edu- 前缀的容器日志
+      - source_labels: ['__meta_docker_container_name']
+        regex: '/(edu-.*).*'
+        action: keep
+      # 提取容器名作为 label
+      - source_labels: ['__meta_docker_container_name']
+        regex: '/(.*)'
+        target_label: container_name
+      # 提取镜像名
+      - source_labels: ['__meta_docker_container_log_stream']
+        target_label: stream