feat: add geolocation support with Near Me button and user location marker on map

- Add "Near Me" button to SearchBar with loading state and geolocation via postcodes.io API
- Display user location on map with pulsing blue marker using geolocation API with IP fallback
- Adjust map zoom level based on search radius for better context
- Pass radiusMiles prop from

resources/js/views/Home.vue

@@ -118,7 +118,7 @@
                         <span class="font-medium">No stations found near you. Try a different postcode or increase the radius.</span>
                     </div>
                     <template v-else>
-                        <LeafletMap :stations="stations" :default-open="true" />
+                        <LeafletMap :default-open="true" :radius-miles="radiusMiles" :stations="stations" />
                         <StationList :stations="stations" :current-sort="sort" @sort="onSort" />
                     </template>
                 </template>
@@ -423,10 +423,12 @@ const { stations, loading, error, search } = useStations()
 const sort = ref('price')
 const lastParams = ref(null)
 const searchAttempted = ref(false)
+const radiusMiles = ref(10)
 
 async function onSearch(params) {
     lastParams.value = params
     sort.value = params.sort ?? sort.value
+    radiusMiles.value = params.radius ?? radiusMiles.value
     searchAttempted.value = true
     await search(params)
 }