Add isPointInPolygon utility function for polygon containment checks

Implements ray-casting algorithm to determine if a point lies within a polygon boundary.

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

Co-Authored-By: David Nguyen <david.nguyen@goutezplanb.com>
Co-Authored-By: Claude <noreply@anthropic.com>

projects/ngx-open-map-wrapper/src/lib/adapters/map-adapter.interface.ts

@@ -24,6 +24,29 @@ export function getLngLat(latLng: LatLng): [number, number] {
   return [latLng[1], latLng[0]];
 }
 
+export function isPointInPolygon(polygon: LatLng[], point: LatLng): boolean {
+  let intersections = 0;
+  const x = point[0]; // lat
+  const y = point[1]; // lng
+
+  for (let i = 0; i < polygon.length; i++) {
+    const nextIndex = (i + 1) % polygon.length;
+    const x1 = polygon[i][0]; // lat
+    const y1 = polygon[i][1]; // lng
+    const x2 = polygon[nextIndex][0]; // lat
+    const y2 = polygon[nextIndex][1]; // lng
+
+    if ((y1 > y) !== (y2 > y)) {
+      const intersectionX = ((x2 - x1) * (y - y1)) / (y2 - y1) + x1;
+      if (x < intersectionX) {
+        intersections++;
+      }
+    }
+  }
+
+  return intersections % 2 === 1;
+}
+
 export interface RouteLineStyle {
   color?: string;
   opacity?: number;