Add map stations feature with Leaflet integration; update EstacioXema model and enhance routing

package.json

@@ -19,7 +19,9 @@
     "@angular/material": "^21.2.11",
     "@angular/platform-browser": "^21.2.0",
     "@angular/router": "^21.2.0",
+    "@types/leaflet": "^1.9.21",
     "chart.js": "^4.5.1",
+    "leaflet": "^1.9.4",
     "moment": "^2.30.1",
     "ng2-charts": "^10.0.0",
     "rxjs": "~7.8.0",