Test E2Es against packaged service instead of workspace link

[goosewobbler]

Currently E2E tests use workspace links which can mask packaging issues that only appear in real installations. We should test against the packaged version of the service. Doing so will negate the need for manual testing with wdio-electron-service-example.

Approach:

1. Create TestAppsManager to:

   • Package service with pnpm pack
   • Copy apps to temp dir
   • Replace workspace links with packaged service
   • Install dependencies

2. Update test infrastructure:

   • Single preparation run
   • Proper temp directory cleanup
   • Update CI workflow

This will catch packaging and module resolution issues earlier by testing the service as users would consume it.