chore(deps-dev): bump @modelcontextprotocol/sdk from 1.25.3 to 1.26.0

Bumps [@modelcontextprotocol/sdk](https://github.com/modelcontextprotocol/typescript-sdk) from 1.25.3 to 1.26.0.
- [Release notes](https://github.com/modelcontextprotocol/typescript-sdk/releases)
- [Commits](modelcontextprotocol/typescript-sdk@v1.25.3...v1.26.0)

---
updated-dependencies:
- dependency-name: "@modelcontextprotocol/sdk"
  dependency-version: 1.26.0
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

packages/ai-proxy/package.json

@@ -21,7 +21,7 @@
     "zod": "^4.3.5"
   },
   "devDependencies": {
-    "@modelcontextprotocol/sdk": "1.25.3",
+    "@modelcontextprotocol/sdk": "1.26.0",
     "@types/express": "5.0.1",
     "express": "5.1.0",
     "node-zendesk": "6.0.1"