* feat: add automated PR review workflow via Vertex AI Gemini
* fix: use workflow name instead of job_workflow_ref for WIF mapping
* fix: read review output from file to avoid JS syntax errors in github-script
* chore: remove redundant GITHUB_OUTPUT logic in PR review workflow
* chore: move configuration identifiers to GitHub Variables
* chore: upgrade model to 3.1-pro-preview and sanitize comment title
* fix: use full model path in vertex ai SDK for preview models
* fix: revert to gemini-2.5-pro due to Vertex API model resolution errors