feat(worker): 实现集群限流与自适应负载

保留平台模型 RPM、TPM 和并发策略语义，增加 PostgreSQL 集群级租约、饱和候选重选和多平台自动负载，避免突发任务固定等待首个平台。\n\n新增 Worker 实时负载采样、自适应 active/heavy 容量、心跳与管理端指标，并扩展本地 acceptance runner，覆盖三 Worker、同模型三平台 2/4/6 并发和 48 个带图视频突发任务。\n\n验证：go test ./...、go vet ./...、PostgreSQL 跨 Store 集成测试、gofmt、bash -n、ShellCheck 及本地集群 provider-burst 验收通过；48/48 成功，无越限、重复提交、重复计费、重复回调或终态资源泄漏。

apps/api/docs/swagger.json

@@ -2575,6 +2575,30 @@
                 }
             }
         },
+        "/api/admin/runtime/workers": {
+            "get": {
+                "security": [
+                    {
+                        "BearerAuth": []
+                    }
+                ],
+                "produces": [
+                    "application/json"
+                ],
+                "tags": [
+                    "acceptance"
+                ],
+                "summary": "获取集群 Worker 实时负载与领取容量",
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/store.WorkerClusterRuntime"
+                        }
+                    }
+                }
+            }
+        },
         "/api/admin/system/acceptance/capacity-profiles": {
             "get": {
                 "security": [
@@ -16347,6 +16371,108 @@
                     "$ref": "#/definitions/store.GatewayWalletAccount"
                 }
             }
+        },
+        "store.WorkerClusterRuntime": {
+            "type": "object",
+            "properties": {
+                "capturedAt": {
+                    "type": "string"
+                },
+                "queue": {
+                    "$ref": "#/definitions/store.WorkerQueueRuntime"
+                },
+                "workers": {
+                    "type": "array",
+                    "items": {
+                        "$ref": "#/definitions/store.WorkerInstanceRuntime"
+                    }
+                }
+            }
+        },
+        "store.WorkerInstanceRuntime": {
+            "type": "object",
+            "properties": {
+                "activeLeases": {
+                    "type": "integer"
+                },
+                "allocatedCapacity": {
+                    "type": "integer"
+                },
+                "capacityLimit": {
+                    "type": "integer"
+                },
+                "drainingAt": {
+                    "type": "string"
+                },
+                "finalizingTasks": {
+                    "type": "integer"
+                },
+                "hardCapacityLimit": {
+                    "type": "integer"
+                },
+                "heartbeatAt": {
+                    "type": "string"
+                },
+                "heavyCapacity": {
+                    "type": "integer"
+                },
+                "instanceId": {
+                    "type": "string"
+                },
+                "loadSampledAt": {
+                    "type": "string"
+                },
+                "podName": {
+                    "type": "string"
+                },
+                "podUid": {
+                    "type": "string"
+                },
+                "preparingTasks": {
+                    "type": "integer"
+                },
+                "pressureReason": {
+                    "type": "string"
+                },
+                "pressureState": {
+                    "type": "string"
+                },
+                "reportedActiveTasks": {
+                    "type": "integer"
+                },
+                "revision": {
+                    "type": "string"
+                },
+                "runningTasks": {
+                    "type": "integer"
+                },
+                "safeCapacity": {
+                    "type": "integer"
+                },
+                "site": {
+                    "type": "string"
+                },
+                "status": {
+                    "type": "string"
+                },
+                "waitingUpstreamTasks": {
+                    "type": "integer"
+                }
+            }
+        },
+        "store.WorkerQueueRuntime": {
+            "type": "object",
+            "properties": {
+                "oldestWaitSeconds": {
+                    "type": "number"
+                },
+                "queued": {
+                    "type": "integer"
+                },
+                "running": {
+                    "type": "integer"
+                }
+            }
         }
     },
     "securityDefinitions": {