ASA Go: Spike - Decouple push notifications from SFMS pipeline

**Describe the task**
Currently push notifications are coupled to the 8am SFMS run. Stakeholders have indicated that 8am may be too late for staff to receive notifications and would like to see notifications pushed earlier in the morning (6am).

As weather forecasts may not change significantly between 3:45pm yesterday and 6-8am today, we should explore decoupling push notifications from the SFMS and instead use a cronjob to push out the notifications for advisories/warnings based on the results of yesterday's 3:45pm forecast SFMS run.

**Acceptance Criteria**
- [ ] first
- [ ] second
- [ ] third

**Additional context**
- Add any other context about the task here.
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No files, tests, or entry points are named. Start by tracing the current SFMS pipeline and 8am push-notification path, then identify what would be needed to use yesterday's 3:45pm forecast results for an earlier scheduled notification. Done requires an agreed approach and concrete acceptance criteria for the 6am timing and decoupling.

Written by the indexing model from the issue text.