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/store/slices/placesSlice.ts

@@ -12,6 +12,7 @@ export interface PlacesSlice {
   addPlace: (tripId: number | string, placeData: Partial<Place>) => Promise<Place>
   updatePlace: (tripId: number | string, placeId: number, placeData: Partial<Place>) => Promise<Place>
   deletePlace: (tripId: number | string, placeId: number) => Promise<void>
+  deletePlacesMany: (tripId: number | string, placeIds: number[]) => Promise<void>
 }
 
 export const createPlacesSlice = (set: SetState, get: GetState): PlacesSlice => ({
@@ -80,4 +81,28 @@ export const createPlacesSlice = (set: SetState, get: GetState): PlacesSlice =>
       throw new Error(getApiErrorMessage(err, 'Error deleting place'))
     }
   },
+
+  deletePlacesMany: async (tripId, placeIds) => {
+    if (placeIds.length === 0) return
+    try {
+      await placeRepo.deleteMany(tripId, placeIds)
+      const idSet = new Set(placeIds)
+      set(state => {
+        const updatedAssignments = { ...state.assignments }
+        let changed = false
+        for (const [dayId, items] of Object.entries(state.assignments)) {
+          if (items.some((a: Assignment) => a.place?.id != null && idSet.has(a.place.id))) {
+            updatedAssignments[dayId] = items.filter((a: Assignment) => !idSet.has(a.place?.id!))
+            changed = true
+          }
+        }
+        return {
+          places: state.places.filter(p => !idSet.has(p.id)),
+          ...(changed ? { assignments: updatedAssignments } : {}),
+        }
+      })
+    } catch (err: unknown) {
+      throw new Error(getApiErrorMessage(err, 'Error deleting places'))
+    }
+  },
 })