chore: bump ext-apps to 1.4.0 (#582)

* chore: bump ext-apps to 1.4.0

Changes since 1.3.2:

SDK
- feat: add addEventListener/removeEventListener with DOM-model on* semantics (#573)

pdf-server
- feat: add save_as interact action (#580)
- feat: fit-to-page on fullscreen + pinch-to-zoom (#583)
- fix: npx DOMMatrix crash + broken MCPB bundle (#584)
- fix: viewer liveness, 1:1 batch results, fullscreen jitter (#579)
- fix: render page before O(numPages) annotation scans (#581)
- fix: radio + dropdown in fill_form/save (#577)

Dependencies
- chore: npm audit fix — sdk 1.29.0, systeminformation 5.31.5, +13 transitives (#585, #586)
- fix: bump path-to-regexp 8.3.0 → 8.4.1 to patch ReDoS CVEs (#576)

* chore: update e2e snapshots [skip ci]

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Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

package.json

@@ -5,7 +5,7 @@
     "url": "https://github.com/modelcontextprotocol/ext-apps"
   },
   "homepage": "https://github.com/modelcontextprotocol/ext-apps",
-  "version": "1.3.2",
+  "version": "1.4.0",
   "license": "MIT",
   "description": "MCP Apps SDK — Enable MCP servers to display interactive user interfaces in conversational clients.",
   "type": "module",