Two bugs in the channel-enabled affordance:
1. List-row toggle was a static span with no handler; the row's
row-link overlay swallowed every click and routed to /edit. Add
POST /settings/notifications/{id}/toggle backed by a new store
method SetNotificationChannelEnabled, and turn the row toggle
into an htmx-driven button that swaps in the new state. Use
event.stopPropagation() on the toggle so it beats the row link.
2. Edit-form toggle visually flipped but the underlying checkbox
reverted: the visual span lives inside the <label>, so clicking
it fired the inline JS handler AND the label's native
checkbox-toggle, cancelling out. Bind to the checkbox 'change'
event instead and let the label do the toggling — the JS just
mirrors check.checked into the .on class.
steve