Governs the on-device Drift/SQLite data layer: package:drift and package:sqlite3 confined to lib/data/ behind DAOs that map rows to immutable value objects (no Drift symbol leaks past the repository), invariants pushed into the schema (STRICT tables, CHECK/FK/partial-UNIQUE indexes), foreign_keys/WAL pragmas re-asserted idempotently in beforeOpen, one db.transaction per mutation, persist-before-publish, every query awaited, canonical integer storage, derived state recomputed-on-read never stored, scoped .watch streams, keyset (seek) pagination not OFFSET, and WAL-safe backups (checkpoint + VACUUM INTO, verify-by-reopen, never File.copy a live WAL DB). Use when defining or…
