Add full Mini MoonBoard 2020 support

[marcodejongh]

Context

The MoonBoard problem dump import (from problems_2023_01_30/) includes 3,670 problems for the Mini MoonBoard 2020 layout. The layout config and climb data have been added, but full UI support is still needed.

Remaining Work

• Hold set overlay images - Add images for the 4 Mini MoonBoard 2020 hold sets (Original School Holds, Wooden Holds, Wooden Holds B, Wooden Holds C) to public/images/minimoonboard2020/
• Grid rendering adjustments - The Mini MoonBoard uses columns A-K but only rows 2-12 (not the standard 1-18). The grid renderer may need adjustments to handle this smaller grid
• Board background image - Source or create the Mini MoonBoard 2020 background board image
• UI route support - Ensure the mini-moonboard-2020 layout key works in the URL routing and layout selection UI
• Testing - Verify climb display, hold overlay positioning, and search/filtering work correctly for Mini MoonBoard 2020 problems

Notes

• Layout ID: 6
• Hold set IDs: 24-27
• Config added in packages/web/app/lib/moonboard-config.ts
• 3,670 problems imported into board_climbs with layout_id=6, angle=40