feat: remove Supabase, bundle questions locally, use JSON DB + API

feat: improve UX and player tracking

feat: add Spark Micro-Debate Arena

polish: Master's Lair visual tuning and z-index fixes

feat: replace Master's Lair with WebGL cosmic descent

refactor: unify home page flow to eliminate redundant landing screen and use modal name entry

feat: cinematic landing page with 3D title, scroll easter egg, and starfield preservation

feat: redesign landing page with floating tiles, hero pillars, scoring transparency