Organize and clean up ui project, fix lint errors and audit

[godofecht]

Removed unused ArenaPanel component and its associated imports/interfaces in ui/src/App.tsx. Updated ui/vite.config.ts to use import.meta.dirname. Ran npm audit and updated the package-lock.json file. Re-built the Vite bundle.

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PR created automatically by Jules for task 8559482800629467108 started by @godofecht

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