fix: refine server helper types

- Make RESOURCE_URI_META_KEY required in McpUiAppToolConfig (tools need a UI resource)
- Make _meta optional in McpUiAppResourceConfig (not all resources need custom metadata)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: ochafik

src/server/index.ts

@@ -49,7 +49,7 @@ export interface McpUiAppToolConfig extends ToolConfig {
      *
      * @example "ui://weather/widget.html"
      */
-    [RESOURCE_URI_META_KEY]?: string;
+    [RESOURCE_URI_META_KEY]: string;
     [key: string]: unknown;
   };
 }
@@ -58,8 +58,8 @@ export interface McpUiAppToolConfig extends ToolConfig {
  * MCP App Resource configuration for `registerAppResource`.
  */
 export interface McpUiAppResourceConfig extends ResourceMetadata {
-  _meta: {
-    ui: McpUiResourceMeta;
+  _meta?: {
+    ui?: McpUiResourceMeta;
     [key: string]: unknown;
   };
 }