Cloudflare Workers CD with auto-rollback

A three-workflow CD setup:

• deploy.yml (reusable, workflow_call) — the actual deploy chain: capture pre-deploy version_id → apply D1 migrations → build → deploy → smoke → auto-rollback if smoke failed → summary report.
• cd-staging.yml — fires on push to main, calls deploy.yml with environment: staging.
• cd-production.yml — fires on push to release, calls deploy.yml with environment: production.

The chain catches production-only bugs (BigInt hangs, missing env, region-only routing) without a human in the loop — failed smoke automatically restores the previous Worker version.

When to invoke

Use when you're:

• Setting up CD for a new Cloudflare Worker and want safety beyond "wrangler deploy".
• Adding rollback to an existing manual-deploy project.
• Debugging a deploy that should have rolled back but didn't — the common causes are documented in references/cd-traps.md.

Pipeline shape