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/web/src/api.ts

@@ -59,6 +59,7 @@ import type {
   WalletBalanceAdjustmentRequest,
   WalletRechargeRequest,
   WalletSummaryResponse,
+  WorkerClusterRuntime,
 } from '@easyai-ai-gateway/contracts';
 import type { AdminTaskQuery, PlatformCreateInput, PlatformModelBindingInput, WorkspaceTaskQuery } from './types';
 
@@ -1037,6 +1038,10 @@ export async function listModelRateLimitStatuses(token: string): Promise<ListRes
   return request<ListResponse<ModelRateLimitStatus>>('/api/admin/runtime/model-rate-limits', { token });
 }
 
+export async function getWorkerClusterRuntime(token: string): Promise<WorkerClusterRuntime> {
+  return request<WorkerClusterRuntime>('/api/admin/runtime/workers', { token });
+}
+
 export async function restoreModelRuntimeStatus(token: string, platformModelId: string): Promise<ModelRateLimitStatus> {
   return request<ModelRateLimitStatus>(`/api/admin/runtime/model-rate-limits/${platformModelId}/restore`, {
     method: 'POST',