SCHEDULER ENHANCEMENT:
- After each hourly auction scrape, automatically match new auctions
against all active Sniper Alerts
- _auction_matches_alert() checks all filter criteria:
- Keyword matching
- TLD whitelist
- Min/max length
- Min/max price
- Exclude numbers
- Exclude hyphens
- Exclude specific characters
- Creates SniperAlertMatch records for dashboard display
- Sends email notifications to users with matching alerts
- Updates alert's last_triggered timestamp
This implements the full Sniper Alert workflow from analysis_3.md:
'Der User kann extrem spezifische Filter speichern.
Wenn die Mail kommt, weiß der User: Das ist relevant.'