Firmware, Increase LED flashing rate based on alarm severity

[nk25719]

Description

Test the current LED behavior for alarm levels 1–5. Update it so the flashing urgency increases with the alarm severity.

Tasks

• Define the flash rate or pattern for each level.
• Make higher alarm levels flash more urgently.
• Define behavior when multiple alarms are active.

Acceptance criteria

• Every alarm level has a defined LED pattern.
• Flashing urgency increases with severity.
• The highest active alarm controls the LED indication.
• Clearing or acknowledging alarms updates the LED correctly.