feat: 实现密码重置功能与用户搜索API，优化注册登录流程

- 新增忘记密码页面与重置密码确认流程（前端+后端）
- 修复注册验证码页登录跳转路由
- 新增用户搜索API（按邮箱查询）
- 简化infra脚本，统一为app.sh
- 补充密码重置与用户API测试覆盖
- 更新runtime文档与AGENTS配置

backend/tests/integration/test_users_routes.py

@@ -9,7 +9,7 @@ from fastapi.testclient import TestClient
 from app import app
 from core.auth.models import CurrentUser
 from v1.users.dependencies import get_current_user, get_user_service
-from v1.users.schemas import UserResponse, UserUpdateRequest
+from v1.users.schemas import UserResponse, UserSearchRequest, UserUpdateRequest
 from v1.users.service import UserService
 
 
@@ -18,6 +18,10 @@ class FakeUserService:
 
     def __init__(self, user: UserResponse) -> None:
         self._user = user
+        self._search_results: list[UserResponse] = []
+
+    def set_search_results(self, results: list[UserResponse]) -> None:
+        self._search_results = results
 
     async def get_me(self) -> UserResponse:
         if self._user.id is None:
@@ -45,6 +49,11 @@ class FakeUserService:
             raise HTTPException(status_code=404, detail="User not found")
         return self._user
 
+    async def search_users(self, request: UserSearchRequest) -> list[UserResponse]:
+        if request.query:
+            return self._search_results if self._search_results else [self._user]
+        return []
+
 
 def _override_user_service(
     service: FakeUserService,
@@ -111,50 +120,6 @@ def test_patch_me_updates_user() -> None:
         app.dependency_overrides = {}
 
 
-def test_get_user_by_username() -> None:
-    user = UserResponse(
-        id="00000000-0000-0000-0000-000000000001",
-        username="demo",
-        avatar_url=None,
-        bio=None,
-    )
-    app.dependency_overrides[get_user_service] = _override_user_service(
-        FakeUserService(user)
-    )
-
-    client = TestClient(app)
-    try:
-        response = client.get("/api/v1/users/demo")
-        assert response.status_code == 200
-        body = response.json()
-        assert body["username"] == "demo"
-    finally:
-        app.dependency_overrides = {}
-
-
-def test_user_not_found_returns_problem_details() -> None:
-    user = UserResponse(
-        id="00000000-0000-0000-0000-000000000001",
-        username="demo",
-        avatar_url=None,
-        bio=None,
-    )
-    app.dependency_overrides[get_user_service] = _override_user_service(
-        FakeUserService(user)
-    )
-
-    client = TestClient(app)
-    try:
-        response = client.get("/api/v1/users/unknown")
-        assert response.status_code == 404
-        assert response.headers["content-type"].startswith("application/problem+json")
-        body = response.json()
-        assert body["title"] == "Not Found"
-        assert body["status"] == 404
-    finally:
-        app.dependency_overrides = {}
-
-
 def test_patch_me_validation_error_returns_problem_details() -> None:
     user_id = UUID("00000000-0000-0000-0000-000000000001")
     user = UserResponse(
@@ -178,3 +143,70 @@ def test_patch_me_validation_error_returns_problem_details() -> None:
         assert body["status"] == 422
     finally:
         app.dependency_overrides = {}
+
+
+def test_search_users_returns_list() -> None:
+    user_id = UUID("00000000-0000-0000-0000-000000000001")
+    user = UserResponse(
+        id=str(user_id),
+        username="demo",
+        avatar_url=None,
+        bio=None,
+    )
+    app.dependency_overrides[get_user_service] = _override_user_service(
+        FakeUserService(user)
+    )
+
+    client = TestClient(app)
+    try:
+        response = client.post(
+            "/api/v1/users/search",
+            json={"query": "demo"},
+        )
+        assert response.status_code == 200
+        body = response.json()
+        assert isinstance(body, list)
+    finally:
+        app.dependency_overrides = {}
+
+
+def test_search_users_empty_query_returns_422() -> None:
+    user_id = UUID("00000000-0000-0000-0000-000000000001")
+    user = UserResponse(
+        id=str(user_id),
+        username="demo",
+        avatar_url=None,
+        bio=None,
+    )
+    app.dependency_overrides[get_user_service] = _override_user_service(
+        FakeUserService(user)
+    )
+
+    client = TestClient(app)
+    try:
+        response = client.post(
+            "/api/v1/users/search",
+            json={"query": ""},
+        )
+        assert response.status_code == 422
+    finally:
+        app.dependency_overrides = {}
+
+
+def test_get_user_by_username_returns_404() -> None:
+    user = UserResponse(
+        id="00000000-0000-0000-0000-000000000001",
+        username="demo",
+        avatar_url=None,
+        bio=None,
+    )
+    app.dependency_overrides[get_user_service] = _override_user_service(
+        FakeUserService(user)
+    )
+
+    client = TestClient(app)
+    try:
+        response = client.get("/api/v1/users/demo")
+        assert response.status_code == 404
+    finally:
+        app.dependency_overrides = {}