# Change: Add Schedule Triggers

## Why
MED-008: The `Trigger Conditions` requirement includes time-based triggers (cron expressions), but the execution logic is not implemented. The scheduler setup exists for weekly reports but schedule-type triggers cannot be executed.

## What Changes
- Implement cron expression parsing for schedule triggers
- Add scheduler job for evaluating schedule triggers
- Support deadline reminder triggers

## Impact
- Affected specs: automation
- Affected code:
  - `backend/app/services/trigger_service.py` (modify)
  - `backend/app/services/trigger_scheduler.py` (new)
  - `backend/app/scheduler.py` (modify)