- Add SqliteForeignKeyInterceptor (DbConnectionInterceptor) registered via
OnConfiguring so every IDbContextFactory-created context runs
PRAGMA foreign_keys=ON, not only the MigrateAndConfigure context.
- DefaultListsSeeder: replace TOCTOU read-then-insert with atomic
INSERT … SELECT … WHERE NOT EXISTS — one SQLite writer lock, no race.
- AppSettingsRepository.GetAsync: catch DbUpdateException on the
get-or-create path and re-read so concurrent startup cannot throw.
- Migration 20260609000000_UniqueListName: de-duplicates empty list rows
(startup-race leftovers) then adds a UNIQUE index on lists.name.
- ForeignKeyTests: verifies ON DELETE SET NULL (blocked_by_task_id) is
enforced on a fresh DbContext with no manual PRAGMA call.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>