Scraper changes (all 6 sources):
- Add first_seen: date the hash_id was first scraped, never overwritten
- Add last_changed: date the price last changed (= first_seen when new)
- PSN and CityHome load previous output as a lightweight cache to compute these fields
- merge_and_map.py preserves earliest first_seen when deduplicating cross-source duplicates
Map popup:
- Show "Přidáno: YYYY-MM-DD" and "Změněno: YYYY-MM-DD" in each property popup
- NOVÉ badge and pulsing marker now driven by first_seen == today (more accurate than scraped_at)
Map filters (sidebar):
- New "Přidáno / změněno" dropdown: 1, 2, 3, 4, 5, 7, 14, 30 days or all
- Clickable price/m² legend bands: click to filter to that band, multi-select supported
- "✕ Zobrazit všechny ceny" reset link appears when any band is active
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
