Dark mode: CSS custom properties + .dark class toggled via Redux/localStorage,
with a theme toggle in the Header and Settings page. Foundation didn't exist
yet despite prior assumption, so it was built from scratch.
SQLite: new DB_ENGINE=mongo|sqlite env var selects the metadata backend at
runtime (Mongo stays default, no behavior change unless opted in). File/thumbnail
bytes continue to use the existing fs/S3 storage path. Implemented via a shared
DB interface (dbTypes.ts) with parallel mongoDB/ and sqliteDB/ implementations,
selected through dbFactory.ts, with JWT/encryption logic extracted into
userCrypto.ts so both engines share it.
oxmc
subnub