feat: add data sources config system and Earth API integration

- Add data_sources.yaml for configurable data source URLs
- Add data_sources.py to load config with database override support
- Add arcgis_landing_points and arcgis_cable_landing_relation collectors
- Change visualization API to query arcgis_landing_points
- Add /api/v1/datasources/configs/all endpoint
- Update Earth to fetch from API instead of static files
- Fix scheduler collector ID mappings

backend/app/services/scheduler.py

@@ -30,7 +30,9 @@ COLLECTOR_TO_ID = {
     "telegeography_landing": 10,
     "telegeography_systems": 11,
     "arcgis_cables": 15,
-    "fao_landing_points": 16,
+    "arcgis_landing_points": 16,
+    "arcgis_cable_landing_relation": 17,
+    "fao_landing_points": 18,
 }