- Remove NeoUserProvider + NeoInstituteProvider from App.tsx startup chain
- Strip user_db_name/school_db_name from CCUser; add school_id (Phase B wires it to Supabase)
- Remove DatabaseNameService from AuthContext and UserContext
- Remove provisionUser() call from login path; API endpoint preserved for Phase B decision
- Simplify UserContext.resolveProfile: fast-path JWT metadata then background Supabase fetch
- Replace user.user_db_name reads in singlePlayerPage + snapshotService with null-safe guards
- Add useDeviceContext hook (desktop/tablet/phone/iwb, persists to localStorage)
App now loads to dashboard without any Neo4j dependency at startup.
Canvas opens to blank TLDraw state; Phase B rebuilds navigation on Supabase.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>