Scheduling and emergency modes

[fabianabarca]

Description

Time/geo-based content windows and alerts.

Acceptance Criteria

• Schedule config and engine
• Emergency override flow
• Tests

[fabianabarca]

Tracked in #1

[gonguma]

Starts: 2025-11-01
Ends: 2025-11-04
Depends on: #2 and #3. Devices must be registered, and connections established before scheduling time-based or geolocation-based alerts can be configured and sent.