fix(vscode): downgrade @types/vscode to match engines.vscode version

Downgrade @types/vscode from ^1.115.0 to ^1.96.0 to match the
engines.vscode specification. Fixes VSIX packaging error.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: aorumbayev

packages/vscode/package.json

@@ -402,7 +402,7 @@
   "devDependencies": {
     "@types/mocha": "^10.0.10",
     "@types/node": "^25.5.2",
-    "@types/vscode": "^1.115.0",
+    "@types/vscode": "^1.96.0",
     "@vscode/test-cli": "^0.0.12",
     "@vscode/test-electron": "^2.5.2",
     "@vscode/vsce": "^3.7.1",