Proof-of-concept proving the SQLite-storage exit criterion from
docs/architecture/proof-of-concept-plan.md §2:
"Schema, migration, and repository pattern are demonstrated."
Also satisfies the SRS-089 acceptance criteria explicitly:
"Storage implementation uses an embedded local data store and
migration mechanism."
Implements:
- A forward-only Migrator over a fixed Migration list, tracking
the applied version via PRAGMA user_version. Each migration is
applied inside an IMMEDIATE transaction; rolled back on failure.
- Three canonical migrations (initial schema, add nickname,
add last_connected_at) demonstrating ALTER TABLE flows.
- A LocalDatabaseRepository implementing both BookmarkRepository
and SettingsRepository traits.
- Bookmark.identity_ref is a reference to a secret name, never
a secret value (cross-checked by the secure-storage spike's
SS-AUD-001/002 scans). This is the SAD-067 separation.
Test suite (11/11 PASS on 2026-05-13):
- migrator brings fresh DB to latest version
- migrator is idempotent (no-op when already current)
- migrator applies only pending versions (catch-up upgrade)
- migrator rejects out-of-order versions
- migrator rejects DB newer than known migrations (downgrade guard)
- failed migration rolls back atomically
- bookmark CRUD round-trip
- bookmark list ordered by recency
- bookmark UNIQUE(host, identity_ref) enforcement
- settings upsert + delete
- open creates file and persists across reopen
Surfaced finding for the decision register: DEC-013 does not pin a
SQLite crate. The PoC uses rusqlite with the bundled feature
(no system libsqlite3 dependency); production code needs an
owner ruling on rusqlite vs. sqlx vs. sea-orm.
Authority: PoC plan §2, SRS-089, SDD-077, SAD-067,
SysDes-033/036/049/091.
Not product code; not promoted into chanora_storage.
