Add three new services for the Forgejo API client:
- ActionsService: repo/org secrets, variables, workflow dispatch
- NotificationService: list, mark read, thread operations
- PackageService: list, get, delete packages and files
Wire up real constructors in forge.go and remove stubs from
services_stub.go. All 21 new tests pass.
Co-Authored-By: Virgil <virgil@lethean.io>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
