chore: update ai package to 6.0.49 across all packages

- Updated all packages from ai@6.0.23 to ai@6.0.49
- Added pnpm override to ensure consistent version
- Created changeset for publishing affected packages

apps/web/package.json

@@ -44,7 +44,7 @@
     "@vercel/analytics": "^1.6.1",
     "@vercel/blob": "^2.0.0",
     "@vercel/kv": "^3.0.0",
-    "ai": "6.0.23",
+    "ai": "6.0.49",
     "better-auth": "^1.4.10",
     "bm25": "^0.1.1",
     "d3": "^7.9.0",