## Summary
- Removes the `IS_APPLICATION_INSTALLATION_FROM_TARBALL_ENABLED` feature
flag, consolidating tarball-based app installation under the existing
`IS_APPLICATION_ENABLED` flag
- Removes the runtime feature flag check in `runWorkspaceMigration`
resolver (the `@RequireFeatureFlag(IS_APPLICATION_ENABLED)` decorator
already gates this endpoint)
- Cleans up related integration test setup/teardown and mock feature
flag maps
## Test plan
- [ ] Verify tarball-based app installation still works when
`IS_APPLICATION_ENABLED` is true
- [ ] Verify app installation is blocked when `IS_APPLICATION_ENABLED`
is false
- [ ] Run `failing-install-application.integration-spec.ts` to confirm
it passes without the removed flag
Made with [Cursor](https://cursor.com)