Add a reason when enabling, disabling, or snoozing monitors

Updating a monitors status now includes an optional "Reason" field. (Disable, Snooze, Change Snooze & Enable)

Anything you enter is saved as a comment on the monitor's Activity tab, alongside the status change, so the context behind the decision stays with the monitor. Reasons support @mentions, like any other monitor comment.

This works for single monitors and for bulk actions from the Monitors list: select the monitors, choose the action, and enter the reason once — it's recorded on every monitor in the selection.