feat: add Update Environment MCP App (#10260)

* feat: add mcpapps experiment flag and helper

### Description
- Adds mcpapps experiment flag to src/experiments.ts.
- Adds applyAppMeta helper function to src/mcp/util.ts to conditionally add UI metadata.
- Adds unit tests for applyAppMeta in src/mcp/util.spec.ts.

### Scenarios Tested
- Unit tests passed.
- Build succeeds.

* chore: address PR comments on experiments and util

### Description
- Fixes applyAppMeta to preserve existing metadata.
- Moves mcpapps flag to be grouped with other MCP experiments.
- Removes as any in util.spec.ts by importing CallToolResult.

### Scenarios Tested
- Build succeeds.
- Lint passes for modified files (ignoring pre-existing warnings).
- Unit tests for applyAppMeta pass.

* 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.

* feat: add Update Environment MCP App

### Description
Adds the Update Environment MCP App, allowing users to switch projects and directories from the UI.

### Scenarios Tested
- Verified build and file changes.

* fix: resolve compilation errors in mcp-update-env-app

* fix: resolve remaining lint errors in mcp-update-env-app

* refactor: extract app MIME type shared constant

Author: joehan

npm-shrinkwrap.json

@@ -185,6 +185,7 @@
     "@angular-devkit/architect": "^0.1402.2",
     "@angular-devkit/core": "^14.2.2",
     "@google/events": "^5.1.1",
+    "@modelcontextprotocol/ext-apps": "^1.3.2",
     "@types/archiver": "^6.0.0",
     "@types/async-lock": "^1.4.2",
     "@types/body-parser": "^1.17.0",

package.json

@@ -184,6 +184,11 @@ export const ALL_EXPERIMENTS = experiments({
     default: false,
     public: true,
   },
+  mcpapps: {
+    shortDescription: "Enables MCP Apps features",
+    fullDescription: "Enables MCP Apps features, including returning UI resource URIs.",
+    public: true,
+  },
   fdcift: {
     shortDescription: "Enable instrumentless trial for SQL Connect",
     default: true,