Redesign the maintenance page

[teslims2]

Description

MaintenancePage is a placeholder. Redesign with an estimated return time, status updates, and a contact link.

This is a frontend task in the Next.js 14 + Tailwind CSS codebase. All UI changes must respect the existing design token system, support both light and dark mode, and meet WCAG AA contrast requirements. New or modified components should be covered by React Testing Library unit tests.

Acceptance Criteria

• Page shows estimated return time (configurable via env var)
• Status update message field (configurable)
• Link to status page (e.g. Uptime Robot)
• Brand-consistent design with livestock illustration
• Page is served as a static HTML fallback during downtime
• Unit/integration tests added or updated to cover the change
• All existing CI checks pass with the change applied
• Component is keyboard-navigable and screen-reader friendly