Add geographic coordinates to IP data and enhance map visualization

- Introduced latitude and longitude fields in the IP data structure to support geographic information.
- Updated the API documentation to reflect the inclusion of geographic coordinates in the unique IPs endpoint.
- Enhanced the UI to display a map of connections using Leaflet, providing a visual representation of IP locations based on the new geographic data.
- Improved the handling of GeoIP data to ensure accurate mapping and user experience when GeoIP is enabled.

internal/geoip/geoip.go

@@ -75,6 +75,8 @@ type Result struct {
 	CountryCode string
 	CountryName string
 	CityName    string
+	Latitude    float64
+	Longitude   float64
 	ASN         uint64
 	ASOrg       string
 }
@@ -99,6 +101,13 @@ func (s *Service) Lookup(ipStr string) (Result, bool) {
 			if rec.City.Names != nil {
 				out.CityName = rec.City.Names["en"]
 			}
+			// Coordinates are used by the UI map.
+			// Note: MaxMind might still return 0/0 for unknown locations.
+			if rec.Location.Latitude != 0 || rec.Location.Longitude != 0 {
+				out.Latitude = rec.Location.Latitude
+				out.Longitude = rec.Location.Longitude
+				ok = true
+			}
 			if out.CountryCode != "" || out.CountryName != "" || out.CityName != "" {
 				ok = true
 			}