feat(acceptance): 建立同构验收与弹性容量体系

实现本地三节点 K3s 同构环境、脱敏生产快照、Gemini 图片和多参考图视频协议模拟、统一验收报告及故障注入。\n\n新增 Worker 容量控制器、资源与连接预算、任务恢复保护，并将生产验收拆分为 validation 执行和人工 CAS 放量。\n\n验证包括 Go 全量测试、PostgreSQL HTTP 集成测试、go vet、OpenAPI、ShellCheck、前端检查、迁移及发布脚本测试。

apps/api/internal/httpapi/gemini_base64_stress_integration_test.go

@@ -74,9 +74,9 @@ func TestGeminiBase64ImageEditThousandSynchronousRequests(t *testing.T) {
 		t.Fatalf("connect observation pool: %v", err)
 	}
 	defer pool.Close()
+	restoreAcceptanceState := isolateHTTPAcceptanceState(t, ctx, pool, true)
+	defer restoreAcceptanceState()
 	if _, err := pool.Exec(ctx, `
-UPDATE integration_platforms SET status = 'disabled' WHERE deleted_at IS NULL;
-UPDATE file_storage_channels SET status = 'disabled' WHERE deleted_at IS NULL;
 UPDATE gateway_user_groups
 SET rate_limit_policy = '{"rules":[
   {"metric":"concurrent","limit":1024,"leaseTtlSeconds":120},