Feature Request: Support --urgent flag for alarm-style reminders

[Allen8858]

Apple recently added an "紧急" (Urgent) toggle in Reminders.app (iOS 18+ / macOS 15+). When enabled, the reminder acts as a persistent alarm that keeps notifying until manually dismissed.

The toggle appears in the reminder detail view with the description: "将此提醒事项标记为紧急以设定闹钟。"

Feature request: add a CLI flag (e.g. --urgent) when creating reminders.

Example:

remindctl add "Important meeting" --list "Work" --due "2026-06-01 14:00" --urgent

This would be very useful for critical reminders that need persistent alerts.

[clawsweeper]

ClawSweeper status: review started.

I am starting a fresh review of this issue: Feature Request: Support --urgent flag for alarm-style reminders This is item 1/1 in the current shard. Shard 0/1.

This placeholder means the worker is alive and reading the current context. I will edit this same comment with the actual review when the claws are done clicking.

Crustacean status: shell secured, claws on keyboard, evidence pebbles being sorted.