feat(apps): add isAppTool helper in core (#1260) (#1272)

* feat(apps): add isAppTool helper in core (#1260)

Adds @modelcontextprotocol/ext-apps as a dependency (root + clients/web)
and a thin core/mcp/apps.ts wrapper exposing:

- getAppResourceUri(tool): re-export of getToolUiResourceUri so all
  Inspector clients consume the same nested/flat _meta resolution.
- isAppTool(tool): boolean predicate built on top of getAppResourceUri.

Both surface the underlying ext-apps throw on a malformed _meta.ui.resourceUri
(string that does not start with "ui://") rather than swallowing it — server
bugs should be visible.

Tests cover nested format, deprecated flat format, nested-wins precedence,
missing _meta, and the invalid-URI throw.

Refs #1260

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* test(apps): address PR #1272 review feedback

- core/mcp/apps.ts: convert getAppResourceUri from a typed const re-export to
  a function declaration so its export style matches isAppTool. Behavior is
  unchanged.
- core/mcp/apps.ts: document the filter-iteration implication on isAppTool —
  callers using tools.filter(isAppTool) will halt on a server-malformed URI.
- apps.test.ts: add the symmetric isAppTool false-case for `_meta.ui` present
  without `resourceUri`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

clients/web/package.json

@@ -24,6 +24,7 @@
     "@mantine/form": "^8.3.17",
     "@mantine/hooks": "^8.3.17",
     "@mantine/notifications": "^8.3.17",
+    "@modelcontextprotocol/ext-apps": "^1.7.1",
     "@modelcontextprotocol/sdk": "^1.29.0",
     "ajv": "^8.17.1",
     "react": "^19.2.4",
@@ -48,12 +49,12 @@
     "@vitejs/plugin-react": "^6.0.0",
     "@vitest/browser-playwright": "^4.1.0",
     "@vitest/coverage-v8": "^4.1.0",
-    "happy-dom": "^20.9.0",
     "eslint": "^9.39.4",
     "eslint-plugin-react-hooks": "^7.0.1",
     "eslint-plugin-react-refresh": "^0.5.2",
     "eslint-plugin-storybook": "^10.2.19",
     "globals": "^17.4.0",
+    "happy-dom": "^20.9.0",
     "playwright": "^1.58.2",
     "prettier": "^3.8.1",
     "storybook": "^10.2.19",