fix: build theme package before config validation in Primary CI

The Primary CI was failing because test:ci:config requires the @ifla/theme
package to be built, but the workflow was skipping the build step to focus
on environment/infrastructure tests only.

Changes:
- Added theme build step before config validation
- This ensures dist/config/index.js exists for config tests
- Maintains Group 5 testing strategy (environment focus)
- Should now show up properly in Nx Cloud

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

Co-Authored-By: Claude <[email protected]>

Author: jonphipps

.github/workflows/nx-optimized-ci.yml

@@ -75,6 +75,10 @@ jobs:
           echo "Running Group 5 CI tests - Environment/Infrastructure Focus"
           echo "Skipping typecheck/lint/unit tests - already validated by pre-commit hooks"
           
+          # Build theme package first (required for config validation)
+          echo "🔧 Building theme package for config validation..."
+          npx nx run @ifla/theme:build
+          
           # Group 5: Environment-specific validation only
           echo "🌐 Running CI connectivity tests..."
           pnpm test:ci:connectivity