fix: Update RegisteredTool to use 'handler' instead of 'callback' (SDK API change)

Author: ochafik

src/app-bridge.test.ts

@@ -655,7 +655,7 @@ describe("App <-> AppBridge integration", () => {
         sendRequest: async () => ({}),
       } as any;
 
-      await expect((tool.callback as any)(mockExtra)).rejects.toThrow(
+      await expect((tool.handler as any)(mockExtra)).rejects.toThrow(
         "Tool test-tool is disabled",
       );
     });
@@ -683,12 +683,12 @@ describe("App <-> AppBridge integration", () => {
 
       // Valid input should work
       await expect(
-        (tool.callback as any)({ name: "Alice" }, mockExtra),
+        (tool.handler as any)({ name: "Alice" }, mockExtra),
       ).resolves.toBeDefined();
 
       // Invalid input should fail
       await expect(
-        (tool.callback as any)({ invalid: "field" }, mockExtra),
+        (tool.handler as any)({ invalid: "field" }, mockExtra),
       ).rejects.toThrow("Invalid input for tool greet");
     });
 
@@ -715,7 +715,7 @@ describe("App <-> AppBridge integration", () => {
       } as any;
 
       // Valid output should work
-      await expect((tool.callback as any)(mockExtra)).resolves.toBeDefined();
+      await expect((tool.handler as any)(mockExtra)).resolves.toBeDefined();
     });
 
     it("tool enable/disable/update/remove trigger sendToolListChanged", async () => {
@@ -856,7 +856,7 @@ describe("App <-> AppBridge integration", () => {
 
       app.oncalltool = async (params, extra) => {
         if (params.name === "greet") {
-          return await (tool.callback as any)(params.arguments || {}, extra);
+          return await (tool.handler as any)(params.arguments || {}, extra);
         }
         throw new Error(`Unknown tool: ${params.name}`);
       };

src/app.ts

@@ -297,7 +297,7 @@ export class App extends Protocol<AppRequest, AppNotification, AppResult> {
         delete app._registeredTools[name];
         app.sendToolListChanged();
       },
-      callback: (async (args: any, extra: RequestHandlerExtra) => {
+      handler: (async (args: any, extra: RequestHandlerExtra) => {
         if (!registeredTool.enabled) {
           throw new Error(`Tool ${name} is disabled`);
         }
@@ -313,7 +313,7 @@ export class App extends Protocol<AppRequest, AppNotification, AppResult> {
           }
           args = parseResult.data;
         }
-        const result = await cb(args, extra);
+        const result = await cb(args, extra as any);
         if (config.outputSchema) {
           const parseResult = await safeParseAsync(
             config.outputSchema as any,
@@ -348,7 +348,7 @@ export class App extends Protocol<AppRequest, AppNotification, AppResult> {
       if (!tool) {
         throw new Error(`Tool ${params.name} not found`);
       }
-      return tool.callback(params.arguments as any, extra);
+      return (tool.handler as any)(params.arguments as any, extra);
     };
     this.onlisttools = async (_params, _extra) => {
       const tools: Tool[] = Object.entries(this._registeredTools)