* fix: Replace platform-wide broadcast_refresh with sync toast
Instead of calling family.broadcast_refresh on every sync completion
(which reloads the page for all connected family members), broadcast
a lightweight static toast to the existing notification-tray.
A new sync-toast Stimulus controller handles two cases:
- User is idle (no focused form): auto-reloads after 500ms
- User is mid-form: toast stays visible with a manual Refresh button
This prevents in-progress form state from being wiped when a background
sync fires (e.g. adding a transaction, filling an import form).
The toast partial contains no user-scoped data, so the Current.user nil
constraint in background jobs is no longer a concern.
* fix(a11y): add explicit button types and aria-label to sync toast controls
* fix(sync-toast): improve interaction detection and replace broadcast strategy
- Increase auto-refresh delay from 500ms to 2000ms
- Expand interaction detection to include contentEditable, dialogs, and role="dialog" elements
- Switch from broadcast_append_to to broadcast_replace_to with dedicated #sync-toast target
- Add explicit id="sync-toast" to partial for targeted replacement
- Move sync_toast i18n keys from defaults/en.yml to views/shared/en.yml
* fix(sync-toast): replace hardcoded white icon color with inverse token
