perf: 优化请求鉴权链路并批量化统计/调度查询

- 为 Pipeline/Context 增加按需读取请求体能力，支持 async 懒加载 JSON body
- 为 chat/cli/video/claude/openai-cli 适配器关闭默认预读，减少无效 body 读取与超时风险
- 将本地登录、JWT 用户加载、API Key 鉴权迁移到线程池隔离会话执行，避免阻塞事件循环
- 为 API Key 鉴权返回结构化余额结果，并在主请求会话中重新绑定 user/api_key 后再校验状态、过期和锁定信息
- 为 management/user token 前缀认证引入独立会话与结果回绑，避免跨会话对象写入失效

- 为 Usage 余额检查补充结构化返回，统一透出 remaining 与欠费/不可用文案映射
- 为用户与管理端活跃请求查询增加 maintain_status 开关，避免轮询指定 id 时误触发状态修复
- 重写 user_me usage 汇总逻辑，支持 group_by=None 的粗粒度聚合
- 修正 provider 维度成功率与平均响应时间统计，基于 success_count 和成功响应耗时汇总计算
- 前端 Usage 轮询由 setInterval 改为串行 setTimeout，避免并发轮询叠加

- 为 StatsAggregator 增加按本地日期批量计算百分位能力，替代逐天 fan-out 查询
- 为混合统计查询合并连续实时日期区间，并批量读取 StatsDaily，减少逐日查询次数
- 为用户日统计增加批量聚合入口，替代逐用户循环聚合
- 为系统配置导出改用 selectinload 预加载 provider 关联数据，减少 N+1 查询
- 为管理员用户列表增加钱包批量查询，避免逐用户回表

- 为调度器增加 provider 轻量引用预过滤，先按 allowed_providers 缩小范围再加载完整 provider 图
- 为 CandidateBuilder 增加 provider refs/provider_ids 查询能力，保留分页顺序
- 为模型缓存增加 provider_model_mappings 索引缓存与 model_mappings 规则缓存，减少重复全量扫描
- 为请求候选中间态改为 flush/batch commit，降低 pending/streaming 状态切换的事务往返
- 为钱包访问结果补充 balance_snapshot，并抽取余额快照复用逻辑

- 补充 pipeline、auth、admin users、user_me usage、stats aggregator、model cache、
  scheduler、wallet、request candidate 等回归与契约测试

tests/api/test_admin_user_routes.py

@@ -0,0 +1,93 @@
+from __future__ import annotations
+
+from datetime import datetime, timezone
+from types import SimpleNamespace
+from typing import Any
+from unittest.mock import MagicMock
+
+import pytest
+from fastapi import FastAPI
+from fastapi.testclient import TestClient
+
+from src.api.admin.users.routes import router as admin_users_router
+from src.database import get_db
+
+
+def _build_admin_users_app(db: MagicMock, monkeypatch: pytest.MonkeyPatch) -> TestClient:
+    app = FastAPI()
+    app.include_router(admin_users_router)
+    app.dependency_overrides[get_db] = lambda: db
+
+    async def _fake_pipeline_run(
+        *, adapter: Any, http_request: object, db: MagicMock, mode: object
+    ) -> Any:
+        _ = http_request, mode
+        context = SimpleNamespace(
+            db=db,
+            request=SimpleNamespace(state=SimpleNamespace()),
+            user=SimpleNamespace(id="admin-1"),
+            ensure_json_body=lambda: {},
+            add_audit_metadata=lambda **_: None,
+        )
+        return await adapter.handle(context)
+
+    monkeypatch.setattr("src.api.admin.users.routes.pipeline.run", _fake_pipeline_run)
+    return TestClient(app)
+
+
+def test_list_users_uses_wallet_batch_lookup(monkeypatch: pytest.MonkeyPatch) -> None:
+    db = MagicMock()
+    client = _build_admin_users_app(db, monkeypatch)
+    now = datetime.now(timezone.utc)
+    users = [
+        SimpleNamespace(
+            id="user-1",
+            email="u1@example.com",
+            username="user1",
+            role=SimpleNamespace(value="user"),
+            allowed_providers=None,
+            allowed_api_formats=None,
+            allowed_models=None,
+            is_active=True,
+            created_at=now,
+            updated_at=now,
+            last_login_at=None,
+        ),
+        SimpleNamespace(
+            id="user-2",
+            email="u2@example.com",
+            username="user2",
+            role=SimpleNamespace(value="admin"),
+            allowed_providers=None,
+            allowed_api_formats=None,
+            allowed_models=None,
+            is_active=True,
+            created_at=now,
+            updated_at=None,
+            last_login_at=None,
+        ),
+    ]
+    wallets_by_user_id = {
+        "user-1": SimpleNamespace(limit_mode="unlimited"),
+    }
+    batch_getter = MagicMock(return_value=wallets_by_user_id)
+
+    monkeypatch.setattr(
+        "src.api.admin.users.routes.UserService.list_users", lambda *_a, **_k: users
+    )
+    monkeypatch.setattr(
+        "src.api.admin.users.routes.WalletService.get_wallets_by_user_ids",
+        batch_getter,
+    )
+    monkeypatch.setattr(
+        "src.api.admin.users.routes.WalletService.get_wallet",
+        lambda *_a, **_k: (_ for _ in ()).throw(AssertionError("不应回退到逐个钱包查询")),
+    )
+
+    response = client.get("/api/admin/users")
+
+    assert response.status_code == 200
+    assert response.json()[0]["unlimited"] is True
+    assert response.json()[1]["unlimited"] is False
+    batch_getter.assert_called_once()
+    assert batch_getter.call_args.args[1] == ["user-1", "user-2"]