fix(build): clear docker build cache to use correct Next.js version (#1075)

* fix: clear Docker build cache to use correct Next.js version

- Changed GitHub Actions cache scope from build-v2 to build-v3
- This should force a fresh build without cached Next.js 15.5.0 layers
- Reverted to ^15.3.2 version format that worked on main branch

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

* run install

---------

Co-authored-by: Claude <noreply@anthropic.com>

.github/workflows/build.yml

@@ -85,8 +85,8 @@ jobs:
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
-          cache-from: type=gha,scope=build-v2
-          cache-to: type=gha,mode=max,scope=build-v2
+          cache-from: type=gha,scope=build-v3
+          cache-to: type=gha,mode=max,scope=build-v3
           provenance: false
           sbom: false