Summary

This change introduces offline support for user-generated question banks backed by Supabase, enabling users to create, read, and sync custom banks both online and offline. It also extends the core flow to source questions from user banks with priority over default templates.

Details

• Add Supabase migrations for user_question_sets and user_questions with per-user Row Level Security (RLS) policies to ensure isolation.
• Extend offline storage to cache, synchronize, and export/import user banks, including a sync state tracker.
• Expand type system to represent user question sets, bank sync state, and question origin metadata.
• Update SessionManager to source questions from user banks when provided, support mixed pools (user banks + templates + defaults), and record provenance (origin/setId/template) for each question.
• Initialize offline data to include storage for user question sets and sync state; include user banks in export/import payloads.
• Add a new migration file (003_user_question_sets.sql) to supabase/migrations for server-side storage.