feat: add secure in-panel updates and global footer

[lrqnet]

Summary

• Add a responsive global footer with author, repository, GitHub Sponsors, installed version, and owner-only update controls.
• Add verified stable-release checking and controlled updates through a dedicated updater service.
• Publish digest-pinned Compose artifacts and fix the responsive header layout.

Security

• Updates use official stable releases, SHA-256 verification, digest-pinned application images, persistent locks, and health checks.
• Updates are blocked while migration operations are active and are owner-only.

Validation

• PHPUnit, Pint, PHPStan
• ESLint, TypeScript, Vite build, translations, public docs
• Compose validation, Docker integration update flow, Chromium E2E
• npm audit, Composer audit, and secret scan