feat: 完善统一端点响应与请求绑定框架

- 新增 IApiResponse 统一响应契约，覆盖普通响应和分页响应
- 扩展端点映射，支持 IApiResponse 和带请求 DTO 的 MapXxx 重载
- 增加 Body、Query、Route Values 到请求 DTO 的自动绑定
- 增加 PC 端路由模式匹配，支持 {id} 和 {id:int}
- API 与 PC 端点上下文补充路由参数传递
- 调整 OpenAPI 请求类型处理，避免 GET/DELETE 被标记为 JSON Body
- 鉴权端点迁移到强类型请求绑定和 IApiResponse 返回
- 增加统一端点文件流响应支持

Avalonia-Services/Extensions/DesktopEndpointAdapter.cs

@@ -109,10 +109,19 @@ namespace Avalonia_Services.Extensions
             Dictionary<string, string>? query = null)
         {
             // 查找匹配的端点（忽略大小写 + 方法匹配）
-            var endpoint = _endpoints.Endpoints.FirstOrDefault(e =>
-                e.SupportsHost(EndpointHostTarget.Pc) &&
-                string.Equals(e.Pattern, path, StringComparison.OrdinalIgnoreCase) &&
-                string.Equals(e.HttpMethod, method, StringComparison.OrdinalIgnoreCase));
+            var match = _endpoints.Endpoints
+                .Where(e =>
+                    e.SupportsHost(EndpointHostTarget.Pc) &&
+                    string.Equals(e.HttpMethod, method, StringComparison.OrdinalIgnoreCase))
+                .Select(e => new
+                {
+                    Endpoint = e,
+                    IsMatched = ServiceEndpointPatternMatcher.TryMatch(e.Pattern, path, out var routeValues),
+                    RouteValues = routeValues,
+                })
+                .FirstOrDefault(candidate => candidate.IsMatched);
+
+            var endpoint = match?.Endpoint;
 
             if (endpoint is null)
             {
@@ -127,6 +136,7 @@ namespace Avalonia_Services.Extensions
                 Body = body,
                 Headers = headers ?? new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase),
                 Query = query ?? new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase),
+                RouteValues = match!.RouteValues,
                 Items = { ["ServiceProvider"] = _serviceProvider },
             };