feat(import): selective GPX/KML element import and performance improvements

Add type-selector UI in the file import modal letting users choose which
GPX elements (waypoints, routes, tracks) or KML/KMZ elements (points,
paths) to import. KML LineString placemarks are now imported as path
places with route_geometry.

Performance improvements:
- Extract MemoPlaceRow with React.memo and contentVisibility:auto to cut
  unnecessary re-renders in PlacesSidebar
- Add weatherQueue to cap concurrent weather fetches at 3
- Replace sequential per-place deletes with a single bulkDelete API call
  (new DELETE /places/bulk endpoint + deletePlacesMany service)
- Memoize atlas/photo/weather service calls to avoid redundant requests
- Add multi-select mode to PlacesSidebar for bulk operations

Add large GPX/KML/KMZ fixtures for integration/perf testing and two
profiler analysis scripts under scripts/.

client/src/components/shared/ConfirmDialog.tsx

@@ -40,7 +40,7 @@ export default function ConfirmDialog({
 
   return (
     <div
-      className="fixed inset-0 z-[60] flex items-center justify-center px-4"
+      className="fixed inset-0 z-[10000] flex items-center justify-center px-4"
       style={{ backgroundColor: 'rgba(15, 23, 42, 0.5)' }}
       onClick={onClose}
     >