feat(server): /metrics 可观测与日志上下文（F22）

- 新增 Prometheus 指标端点 /metrics（HTTP + DB + 作业统计）
- request.log 绑定 requestId/actorId，避免日志难追踪
- cron/pg-boss 作业增加 metrics 计数（runs/processed）
- 更新 env/runbook/README 与 v3 CSV 状态推进

server/package-lock.json

@@ -28,6 +28,7 @@
         "pg": "^8.18.0",
         "pg-boss": "^10.3.0",
         "prisma": "^7.3.0",
+        "prom-client": "^15.1.0",
         "tencentcloud-sdk-nodejs": "^4.1.14",
         "zod": "^4.3.6",
         "zxcvbn": "^4.4.2"
@@ -503,6 +504,15 @@
         "node": ">=16"
       }
     },
+    "node_modules/@opentelemetry/api": {
+      "version": "1.9.0",
+      "resolved": "https://registry.npmjs.org/@opentelemetry/api/-/api-1.9.0.tgz",
+      "integrity": "sha512-3giAOQvZiH5F9bMlMiv8+GSPMeqg0dbaeo58/0SlA9sxSqZhnUtxzX9/2FzyhS9sWQf5S0GJE0AKBrFqjpeYcg==",
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=8.0.0"
+      }
+    },
     "node_modules/@pinojs/redact": {
       "version": "0.4.0",
       "resolved": "https://registry.npmjs.org/@pinojs/redact/-/redact-0.4.0.tgz",
@@ -975,6 +985,12 @@
         "node": "*"
       }
     },
+    "node_modules/bintrees": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/bintrees/-/bintrees-1.0.2.tgz",
+      "integrity": "sha512-VOMgTMwjAaUG580SXn3LacVgjurrbMme7ZZNYGSSV7mmtY6QQRh0Eg3pwIcntQ77DErK1L0NxkbetjcoXzVwKw==",
+      "license": "MIT"
+    },
     "node_modules/bl": {
       "version": "4.1.0",
       "resolved": "https://registry.npmjs.org/bl/-/bl-4.1.0.tgz",
@@ -3046,6 +3062,19 @@
       ],
       "license": "MIT"
     },
+    "node_modules/prom-client": {
+      "version": "15.1.3",
+      "resolved": "https://registry.npmjs.org/prom-client/-/prom-client-15.1.3.tgz",
+      "integrity": "sha512-6ZiOBfCywsD4k1BN9IX0uZhF+tJkV8q8llP64G5Hajs4JOeVLPCwpPVcpXy3BwYiUGgyJzsJJQeOIv7+hDSq8g==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@opentelemetry/api": "^1.4.0",
+        "tdigest": "^0.1.1"
+      },
+      "engines": {
+        "node": "^16 || ^18 || >=20"
+      }
+    },
     "node_modules/proper-lockfile": {
       "version": "4.1.2",
       "resolved": "https://registry.npmjs.org/proper-lockfile/-/proper-lockfile-4.1.2.tgz",
@@ -3540,6 +3569,15 @@
         "node": ">=6"
       }
     },
+    "node_modules/tdigest": {
+      "version": "0.1.2",
+      "resolved": "https://registry.npmjs.org/tdigest/-/tdigest-0.1.2.tgz",
+      "integrity": "sha512-+G0LLgjjo9BZX2MfdvPfH+MKLCrxlXSYec5DaPYP1fe6Iyhf0/fSmJ0bFiZ1F8BT6cGXl2LpltQptzjXKWEkKA==",
+      "license": "MIT",
+      "dependencies": {
+        "bintrees": "1.0.2"
+      }
+    },
     "node_modules/tencentcloud-sdk-nodejs": {
       "version": "4.1.184",
       "resolved": "https://registry.npmjs.org/tencentcloud-sdk-nodejs/-/tencentcloud-sdk-nodejs-4.1.184.tgz",