Providers were moved into the App\Service\Provider namespace, but
services.yaml still tagged/configured them under the old App\Service
FQCNs, so the _instanceof conditional never matched and the container
failed to compile.
Declare empty-string defaults for all optional env vars as Symfony
parameters so the container compiles without errors when GITHUB_USER,
GITLAB_TOKEN, GITEA_URL, etc. are not set in the environment.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>