Drop homepage/GitHub buttons from store extension cards (they remain on
the detail page); keep them only for unlisted extensions whose cards do
not open a detail view. With the labeled update button this caps card
actions at update/settings/delete.
- Update availability is now decided solely by the backend live GitHub
check (updateFlags); the store index may lag and previously masked
new versions in the market view.
- Replace the ambiguous refresh icon on extension cards with a labeled
update button, and add a red dot badge on extension icons (card and
detail view) when an update is available.
- Surface a toast when the update check fails instead of failing silently.