Move Geofence toggle button to map header next to Export

Relocated the "Show/Hide Geofences" toggle button from floating
position (top-right corner) to the main header toolbar.

**Changes:**
- Moved toggle button to header, positioned between Export and Admin buttons
- Converted showGeofences from local state to prop passed from parent
- Button now matches header design system (same styling as Export/Admin)
- Purple background when active, white when inactive
- Better UX: All controls now in one consistent location

**New Button Position:**
Export | Show/Hide Geofences | Admin | Logout

Much cleaner and more intuitive than the floating button!

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

components/map/MapView.tsx

@@ -22,6 +22,7 @@ interface MapViewProps {
   filterMode: "quick" | "custom";
   startTime: string; // datetime-local format
   endTime: string;   // datetime-local format
+  showGeofences: boolean;
 }
 
 interface DeviceInfo {
@@ -67,14 +68,13 @@ function SetViewOnChange({
   return null;
 }
 
-export default function MapView({ selectedDevice, timeFilter, isPaused, filterMode, startTime, endTime }: MapViewProps) {
+export default function MapView({ selectedDevice, timeFilter, isPaused, filterMode, startTime, endTime, showGeofences }: MapViewProps) {
   const [locations, setLocations] = useState<Location[]>([]);
   const [devices, setDevices] = useState<Record<string, DeviceInfo>>({});
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);
   const [mapCenter, setMapCenter] = useState<[number, number] | null>(null);
   const [currentZoom, setCurrentZoom] = useState(12);
-  const [showGeofences, setShowGeofences] = useState(true);
   const intervalRef = useRef<NodeJS.Timeout | null>(null);
 
   // Add animation styles for latest marker
@@ -228,22 +228,7 @@ export default function MapView({ selectedDevice, timeFilter, isPaused, filterMo
   }
 
   return (
-    <div className="h-full w-full relative">
-      {/* Geofence Toggle Button */}
-      <div className="absolute top-4 right-4 z-[1000]">
-        <button
-          onClick={() => setShowGeofences(!showGeofences)}
-          className={`px-4 py-2 rounded-lg shadow-lg font-semibold text-sm transition-all ${
-            showGeofences
-              ? "bg-purple-600 text-white hover:bg-purple-700"
-              : "bg-white text-gray-700 hover:bg-gray-100"
-          }`}
-          title={showGeofences ? "Hide Geofences" : "Show Geofences"}
-        >
-          📍 {showGeofences ? "Hide" : "Show"} Geofences
-        </button>
-      </div>
-
+    <div className="h-full w-full">
       <MapContainer
         center={[48.1351, 11.582]}
         zoom={12}