fix(cli): downgrade AI SDK to v5 for @convex-dev/agent compatibility (#785)

* fix: downgrade AI SDK to v5 for @convex-dev/agent compatibility

@convex-dev/agent@0.3.2 requires ai@^5.0.29, not ai@^6.0.3.
Also downgrade @ai-sdk/* packages to v2.x which return LanguageModelV2.

This fixes TypeScript errors when using the AI example with Convex backend.

Relates to: get-convex/agent#202

* fix: update AI SDK versions to existing npm releases

- ai: ^5.0.117 (5.0.29 does not exist on npm)
- @ai-sdk/google: ^2.0.52 (2.0.0 does not exist on npm)

Addresses CodeRabbit review feedback.

* Revert "fix: update AI SDK versions to existing npm releases"

This reverts commit e2ef101.

* Revert "fix: downgrade AI SDK to v5 for @convex-dev/agent compatibility"

This reverts commit 1650b28.

* add ai in custom deps

---------

Co-authored-by: Aman Varshney <amanvarshney.work@gmail.com>

Author: Noisemaker111

apps/cli/src/helpers/addons/examples-setup.ts

@@ -82,7 +82,11 @@ async function setupAIDependencies(config: ProjectConfig) {
 
   if (backend === "convex" && convexBackendDirExists) {
     await addPackageDependency({
-      dependencies: ["@convex-dev/agent", "ai", "@ai-sdk/google"],
+      dependencies: ["@convex-dev/agent"],
+      customDependencies: {
+        ai: "^5.0.117",
+        "@ai-sdk/google": "^2.0.52",
+      },
       projectDir: convexBackendDir,
     });
   } else if (backend === "self" && webClientDirExists) {