add overloads for registerResource method in McpServer class

Otherwise, TypeScript can't properly distinguish the type of callback

src/server/mcp.ts

@@ -613,6 +613,18 @@ export class McpServer {
    * Registers a resource with a config object and callback.
    * For static resources, use a URI string. For dynamic resources, use a ResourceTemplate.
    */
+  registerResource(
+    name: string,
+    uriOrTemplate: string,
+    config: ResourceMetadata,
+    readCallback: ReadResourceCallback
+  ): RegisteredResource;
+  registerResource(
+    name: string,
+    uriOrTemplate: ResourceTemplate,
+    config: ResourceMetadata,
+    readCallback: ReadResourceTemplateCallback
+  ): RegisteredResourceTemplate;
   registerResource(
     name: string,
     uriOrTemplate: string | ResourceTemplate,