main:删除 Grafana 仪表板配置文件

更新内容：
- 移除 `dashboard.json` 文件，清理不再需要的 Grafana 仪表板配置。
- 简化项目目录结构，删除多余的监控配置以优化维护。

monitoring/promtail.yaml

@@ -0,0 +1,71 @@
+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:
+  # 场景 1: Docker stdio 收集（主要方式）
+  - job_name: docker
+    docker_sd_configs:
+      - host: unix:///var/run/docker.sock
+        refresh_interval: 5s
+        filters:
+          - name: label
+            values: ["logging=promtail"]
+    relabel_configs:
+      - source_labels: ['__meta_docker_container_name']
+        regex: '/(.*)'
+        target_label: 'container'
+      - source_labels: ['__meta_docker_container_label_logging_jobname']
+        target_label: 'job'
+      - source_labels: ['__meta_docker_container_id']
+        target_label: '__path__'
+        replacement: '/var/lib/docker/containers/$1/*.log'
+    pipeline_stages:
+      - json:
+          expressions:
+            log: log
+            stream: stream
+            time: time
+      - json:
+          source: log
+          expressions:
+            level: levelname
+            logger: name
+            message: message
+            request_id: request_id
+      - labels:
+          level:
+          logger:
+      - output:
+          source: log
+
+  # 场景 2: Log 文件收集（备用）
+  - job_name: app_files
+    static_configs:
+      - targets:
+          - localhost
+        labels:
+          job: functional-scaffold-app-files
+          __path__: /var/log/app/*.log
+    pipeline_stages:
+      - json:
+          expressions:
+            timestamp: asctime
+            level: levelname
+            logger: name
+            message: message
+            request_id: request_id
+      - timestamp:
+          source: timestamp
+          format: "2006-01-02 15:04:05,000"
+      - labels:
+          level:
+          logger:
+      - output:
+          source: message