Consider Supabase Realtime instead of polling for notifications

[malharlakdawala]

The notification feed polls every 60 seconds (src/lib/use-notifications.ts). That is deliberate and cheap, but it means a comment can sit unseen for a minute, and every open tab queries the database on a timer all day.

Supabase Realtime could push these instead.

What to think about before building

This is not a straight win, so the investigation is part of the work:

• The taskflow schema is not exposed to the Data API, and anon has no grants (supabase/migrations/20260727092031_taskflow_enable_rls.sql). Realtime would need that changed, which is a security decision, not a detail.
• RLS on Notification already restricts rows to their recipient, which is the right foundation.
• Polling should stay as a fallback for anyone who hasn't enabled Realtime.

Acceptance criteria

• New notifications appear without a refresh, in under a second
• Falls back to polling when Realtime is unavailable
• No new data is exposed to the anon key — argue this explicitly in the PR
• The badge stays correct across multiple open tabs

Worth commenting on the issue with your approach before writing much code.