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/loki.yaml

@@ -0,0 +1,39 @@
+auth_enabled: false
+
+server:
+  http_listen_port: 3100
+  grpc_listen_port: 9096
+
+common:
+  path_prefix: /loki
+  storage:
+    filesystem:
+      chunks_directory: /loki/chunks
+      rules_directory: /loki/rules
+  replication_factor: 1
+  ring:
+    instance_addr: 127.0.0.1
+    kvstore:
+      store: inmemory
+
+schema_config:
+  configs:
+    - from: 2020-10-24
+      store: boltdb-shipper
+      object_store: filesystem
+      schema: v11
+      index:
+        prefix: index_
+        period: 24h
+
+limits_config:
+  retention_period: 168h  # 7 天
+  ingestion_rate_mb: 10
+  ingestion_burst_size_mb: 20
+
+compactor:
+  working_directory: /loki/compactor
+  shared_store: filesystem
+  compaction_interval: 10m
+  retention_enabled: true
+  retention_delete_delay: 2h