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/docker-compose.monitoring.yml

@@ -14,6 +14,8 @@ volumes:
     name: edu-alertmanager-data
   grafana-data:
     name: edu-grafana-data
+  loki-data:
+    name: edu-loki-data
 
 services:
   # ============================================================
@@ -104,16 +106,35 @@ services:
       - edu-network
 
   # ============================================================
-  # blackbox-exporter - 黑盒探测（HTTP / TCP / ICMP）
+  # Loki - 日志聚合（P6 硬化新增）
   # ============================================================
-  blackbox-exporter:
-    image: prom/blackbox-exporter:v0.25.0
-    container_name: edu-blackbox-exporter
+  loki:
+    image: grafana/loki:3.2.1
+    container_name: edu-loki
     profiles: ["monitoring"]
     restart: unless-stopped
+    command: -config.file=/etc/loki/local-config.yaml
     ports:
-      - "9115:9115"
+      - "3100:3100"
     volumes:
-      - ./blackbox/blackbox.yml:/etc/blackbox_exporter/config.yml:ro
+      - loki-data:/loki
     networks:
       - edu-network
+
+  # ============================================================
+  # Promtail - 日志采集（收集 Docker 容器日志发送到 Loki）
+  # ============================================================
+  promtail:
+    image: grafana/promtail:3.2.1
+    container_name: edu-promtail
+    profiles: ["monitoring"]
+    restart: unless-stopped
+    command: -config.file=/etc/promtail/config.yml
+    volumes:
+      - ./promtail/config.yml:/etc/promtail/config.yml:ro
+      - /var/lib/docker/containers:/var/lib/docker/containers:ro
+      - /var/run/docker.sock:/var/run/docker.sock:ro
+    networks:
+      - edu-network
+    depends_on:
+      - loki