feat: add infrastructure for MCP Apps

Adds support for returning structured content from tools, which is used by MCP Apps to pass complex data to the host. Also updates the resource index.

- Verified build and file changes.

Author: joehan

src/mcp/resources/index.ts

@@ -13,6 +13,10 @@ import { ServerResource, ServerResourceTemplate } from "../resource";
 import { trackGA4 } from "../../track";
 import { crashlytics_issues } from "./guides/crashlytics_issues";
 import { crashlytics_reports } from "./guides/crashlytics_reports";
+import { login_ui } from "./login_ui";
+import { update_environment_ui } from "./update_environment_ui";
+import { deploy_ui } from "./deploy_ui";
+import { init_ui } from "./init_ui";
 
 export const resources = [
   app_id,
@@ -25,6 +29,10 @@ export const resources = [
   init_firestore_rules,
   init_auth,
   init_hosting,
+  login_ui,
+  update_environment_ui,
+  deploy_ui,
+  init_ui,
 ];
 
 export const resourceTemplates = [docs];