Theme previously followed only the OS's prefers-color-scheme, which
switches automatically on this user's Mac at sunset/sunrise. Adds an
explicit override in Settings: Light/Dark/System, System being the
previous (default) auto-follow-the-OS behavior.
Persisted client-side in localStorage (lib/theme.ts, same pattern as
language) rather than server-side like currency — it's a pure display
preference, and synchronous localStorage reads are what make the
anti-FOUC inline script in index.html possible. index.css already had the
[data-theme] CSS variables laid in ahead of time; only the JS to actually
set the attribute, and the Settings UI, were missing.
Covered by 2 new Playwright specs (theme-switcher.spec.ts) run against the
isolated e2e stack: explicit choice overrides a dark OS and survives
reload; switching back to "system" doesn't leave a stale forced theme.
Aurum — a self-hosted personal finance operating system: cash flow,
net worth tracking, budgets, goals, recurring payments, reports,
proactive alerts, and a compound-interest returns calculator, all
bilingual (RU/EN) and mobile-first. Ships as a three-container Docker
Compose stack (Postgres + FastAPI + nginx-served React frontend).
See README.md for setup and CONTRIBUTING.md for development.