bug(settings): Reset override row toast-undo not appearing (regression after #113/PR #834)

[cristim]

Repro

1. Navigate to Admin > Purchasing Settings > Service Defaults.
2. Find an override row (a service with a non-default term or payment).
3. Click 'Reset' on that row.

Expected

A toast notification appears with an 'Undo' option. If 'Undo' is clicked, the override value is restored.

Actual

No toast notification appears after resetting an override row. The reset happens silently with no undo option.

Context

Issue #113 was closed as fixed by PR #834. The toast-undo feature has regressed.

Sheet reference

Bugs and improvement suggestions tab, row 536.