- Replace the toast store with a notification store: levels (info/success/
warning/error/fatal), requiresInteraction, and a persisted history.
- Move toasts to the top-right, styled per level, with manual dismiss.
- Add a bell in the header opening a Notification Center (history, unread badge,
'needs attention' vs info, clear all).
- Capture network failures and 5xx responses (api layer) and render crashes
(ErrorBoundary) as notifications.
- Sound + server-sourced events + per-account settings remain for 6b.
- Vite + React + TS + Tailwind SPA served by FastAPI (multi-stage Docker build)
- Four color schemes (Midnight default, Forest, Slate, YouTube) x dark/light,
adjustable text size; persisted to user preferences and localStorage
- Header search, grid/list toggle, theme menu; sidebar filters (show state,
sort, include Shorts/live, language + topic tag chips with any/all matching)
- Infinite-scroll feed of video cards; click opens youtube.com in a new tab;
per-video watched / saved / hidden actions with optimistic updates
- SPA fallback routing; login screen for unauthenticated users
