docs: clarify release deployment process and enable manual deploy trigger

- Add workflow_dispatch to deploy.yml for manual deployment triggers
- Document that releases don't auto-deploy to production
- Add instructions for deploying releases to production
- Add verification steps for deployment

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

Co-Authored-By: Claude <noreply@anthropic.com>

internal/validators/constants.go

@@ -36,4 +36,4 @@ type RepositorySource string
 const (
 	SourceGitHub RepositorySource = "github"
 	SourceGitLab RepositorySource = "gitlab"
-)
+)