Establish protected production release workflow

[faetalize]

Summary

• add Release Drafter for continuously maintained, categorized release notes
• require exactly one release classification on pull requests targeting main
• run the existing merge gate for pull requests targeting production
• document the pinned production promotion and release workflow

Why

Cloudflare now deploys from the permanent production branch. This workflow keeps user-facing release notes current during development and makes release day a controlled promotion from main instead of a manual commit-history audit.

Impact

This is an administrative workflow change with no user-facing application behavior changes.

Validation

• npm run lint
• npm test (125 Vitest tests)
• npm run test:ci (125 Vitest and 21 Playwright tests)
• npm run build
• Prettier and git diff --check

[cloudflare-workers-and-pages]

Deploying zodiac with    Cloudflare Pages

Latest commit:	1077c3d
Status:	✅  Deploy successful!
Preview URL:	https://bc718e9e.zodiac-c9y.pages.dev
Branch Preview URL:	https://feature-transition-to-pinned.zodiac-c9y.pages.dev

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