Build the admin dashboard UI

[Kaushik4141]

Four tabs at /admin. This is a big issue — fine to split it per tab if several people want to take it.

Items

• Table with inline edit and delete, plus an add form
• QR generation per item using the qrcode package, producing ${FRONTEND_URL}/${qrSlug} as a downloadable PNG, plus a "download all as ZIP" action

The QR generation is what makes this app genuinely deployable by a non-developer — without it, running an event means generating codes by hand. Label the tab from config.itemNamePlural, not the literal word "Items".

Results

• Leaderboard sorted by qualified average, with total and qualified voter counts, a completion-rate stat, and CSV export

Settings

• A form over the settings row: names, labels, award, threshold, voting window as datetime pickers, logo paths, sponsor list

Theme

• Colour pickers over the eight semantic tokens, a preset dropdown writing to theme_preset / theme_overrides, and a "reset to preset" action

Blocked by the admin API and routing issues.