feat: 用户列表 API 支持搜索过滤

- GetUserListQuery 增加 Search 参数
- GET /users?search=xxx 按用户名或邮箱模糊搜索

src/RAG.Api/Endpoints/Users/GetUserListEndpoint.cs

@@ -5,7 +5,12 @@ using RAG.Application.Users.Queries;
 
 namespace RAG.Api.Endpoints.Users;
 
-public class GetUserListEndpoint(IMediator mediator) : EndpointWithoutRequest<List<UserDto>>
+public record GetUserListRequest
+{
+    public string? Search { get; init; }
+}
+
+public class GetUserListEndpoint(IMediator mediator) : Endpoint<GetUserListRequest, List<UserDto>>
 {
     public override void Configure()
     {
@@ -13,9 +18,9 @@ public class GetUserListEndpoint(IMediator mediator) : EndpointWithoutRequest<Li
         Permissions("user:read");
     }
 
-    public override async Task HandleAsync(CancellationToken ct)
+    public override async Task HandleAsync(GetUserListRequest req, CancellationToken ct)
     {
-        var result = await mediator.Send(new GetUserListQuery(), ct);
+        var result = await mediator.Send(new GetUserListQuery(req.Search), ct);
         await Send.OkAsync(result, ct);
     }
 }

src/RAG.Application/Users/Queries/GetUserListQuery.cs

@@ -5,14 +5,24 @@ using RAG.Infrastructure.Persistence;
 
 namespace RAG.Application.Users.Queries;
 
-public record GetUserListQuery : IRequest<List<UserDto>>;
+public record GetUserListQuery(string? Search) : IRequest<List<UserDto>>;
 
 public class GetUserListQueryHandler(RagDbContext db) : IRequestHandler<GetUserListQuery, List<UserDto>>
 {
     public async Task<List<UserDto>> Handle(GetUserListQuery request, CancellationToken ct)
     {
-        return await db.Users
+        var query = db.Users
             .Include(u => u.UserRoles).ThenInclude(ur => ur.Role)
+            .AsQueryable();
+
+        if (!string.IsNullOrWhiteSpace(request.Search))
+        {
+            var search = request.Search.ToLower();
+            query = query.Where(u => u.Username.ToLower().Contains(search)
+                || u.Email.ToLower().Contains(search));
+        }
+
+        return await query
             .Select(u => new UserDto(
                 u.Id, u.Username, u.Email, u.IsActive, u.CreatedAt,
                 u.UserRoles.Select(ur => ur.Role.Name).ToList()))