refactor: config/apps 目录重组、文档重构、架构图收窄

- 中央：config/(prometheus,alertmanager,grafana)、apps/(tile-cache,topology-editor)
- 边缘：config/(vmagent,blackbox,targets)、apps/(onvif-exporter)
- env: TRAEFIK_PROVIDER、prometheus/env.example 详细说明
- 文档：README/doc 重构，EDGE_CACHE 合并到 EDGE_AGENT_CONFIG
- targets.csv 更新流程说明，ARCHITECTURE 图收窄

Made-with: Cursor

central-server/config/grafana/dashboards/onvif-monitoring.json

@@ -0,0 +1,76 @@
+{
+  "dashboard": {
+    "id": null,
+    "title": "ONVIF设备监控",
+    "tags": ["onvif", "camera", "monitoring"],
+    "style": "dark",
+    "timezone": "browser",
+    "panels": [
+      {
+        "id": 1,
+        "title": "ONVIF设备状态",
+        "type": "stat",
+        "targets": [
+          {
+            "expr": "up{job=\"onvif-devices\"}",
+            "refId": "A"
+          }
+        ],
+        "fieldConfig": {
+          "defaults": {
+            "color": {
+              "mode": "thresholds"
+            },
+            "thresholds": {
+              "steps": [
+                {
+                  "color": "red",
+                  "value": 0
+                },
+                {
+                  "color": "green",
+                  "value": 1
+                }
+              ]
+            }
+          }
+        },
+        "gridPos": {
+          "h": 8,
+          "w": 12,
+          "x": 0,
+          "y": 0
+        }
+      },
+      {
+        "id": 2,
+        "title": "设备在线率",
+        "type": "gauge",
+        "targets": [
+          {
+            "expr": "sum(up{job=\"onvif-devices\"}) / count(up{job=\"onvif-devices\"}) * 100",
+            "refId": "A"
+          }
+        ],
+        "fieldConfig": {
+          "defaults": {
+            "min": 0,
+            "max": 100,
+            "unit": "percent"
+          }
+        },
+        "gridPos": {
+          "h": 8,
+          "w": 12,
+          "x": 12,
+          "y": 0
+        }
+      }
+    ],
+    "time": {
+      "from": "now-1h",
+      "to": "now"
+    },
+    "refresh": "30s"
+  }
+}