Add durable Cloudflare operation lifecycle

[chubes4]

Summary

• add a D1-backed configured-site registry and durable static-artifact operation lifecycle
• converge duplicate idempotency requests, enforce one active mutation per site, and persist claims, attempts, checkpoints, errors, and retry eligibility
• checkpoint the exact prepared canonical pointer before promotion so restart recovery cannot mistake another mutation at the same version for this operation
• execute bounded work through scheduled invocations, alternate import/publication priority, and expose authenticated read-only operation status
• reconcile immutable publication receipts into terminal operation receipts with SSI, canonical, publication, and site identity

Verification

• npm run test:cloudflare-runtime
• npm run cloudflare:dry-run:d1
• npm run cloudflare:dry-run
• npm run test:cloudflare-wordpress-auth
• npm run test:cloudflare-wordpress-archive-corpus
• git diff --check origin/main...HEAD

Fixes #1973

AI assistance

OpenAI gpt-5.6-sol was used through OpenCode to inspect the existing Cloudflare coordinator architecture, draft the implementation and tests, and review restart/concurrency edge cases. Chris Huber reviewed the resulting behavior, verification evidence, and commit.