Harden Gitea workflow compatibility

[YunaBraska]

Summary

• fix Gitea workflow dispatch/run discovery for issue Gitea workflows not supported completely #89 with Gitea auth, dispatch details, clean browser URLs, and same-workflow fallback matching closest to dispatch time
• avoid false Gitea expression warnings for method-looking text inside quoted shell strings
• add default-on Docker Gitea integration coverage for /api/v1 action and reusable workflow metadata
• add a real act_runner Docker smoke that dispatches a .gitea/workflows run through the plugin client, waits for completion, lists jobs, and downloads logs
• harden .gitea/workflows/* syntax for Gitea permission scopes, cron aliases, GITEA_TOKEN, runner env vars, single-label runs-on, expression functions, and ignored job keys
• keep release automation from stranding a manually pushed tag before gh release create; failed release creation now tries to clean up the release/tag attempt
• document researched Gitea vs GitHub Actions differences and the run-discovery behavior

Notes

Research used official Gitea/GitHub docs for Actions API, token permissions, context variables, and compatibility differences. Docker runner coverage uses Gitea act_runner host mode inside the runner container, which Gitea documents as the direct execution mode when the Docker socket is not mounted.

Checks

• ./gradlew --no-daemon test --tests com.github.yunabraska.githubworkflow.git.GiteaDockerIntegrationTest --rerun-tasks
• ./gradlew --no-daemon check --rerun-tasks
• git diff --check
• PR pipeline: passed on pull_request run https://github.com/YunaBraska/github-workflow-plugin/actions/runs/27533029137
• Branch pipeline: passed on push run https://github.com/YunaBraska/github-workflow-plugin/actions/runs/27533026962
• Release dry-run pipeline: passed on workflow_dispatch run https://github.com/YunaBraska/github-workflow-plugin/actions/runs/27537363149

[absketches]

The PR looks good to me and I have tested the Gitea workflow. There is one minor issue with the plugin detecting strings as method names (attached screenshot).