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/.

server/src/services/weatherService.ts

@@ -95,6 +95,7 @@ const WMO_DESCRIPTION_EN: Record<number, string> = {
 // ── Cache management ────────────────────────────────────────────────────
 
 const weatherCache = new Map<string, { data: WeatherResult; expiresAt: number }>();
+const inFlight = new Map<string, Promise<WeatherResult>>();
 const CACHE_MAX_ENTRIES = 1000;
 const CACHE_PRUNE_TARGET = 500;
 const CACHE_CLEANUP_INTERVAL = 5 * 60 * 1000; // 5 minutes
@@ -146,7 +147,7 @@ export function estimateCondition(tempAvg: number, precipMm: number): string {
 
 // ── getWeather ──────────────────────────────────────────────────────────
 
-export async function getWeather(
+async function _getWeatherImpl(
   lat: string,
   lng: string,
   date: string | undefined,
@@ -281,9 +282,27 @@ export async function getWeather(
   return result;
 }
 
+export async function getWeather(
+  lat: string,
+  lng: string,
+  date: string | undefined,
+  lang: string,
+): Promise<WeatherResult> {
+  const ck = cacheKey(lat, lng, date);
+  const cached = getCached(ck);
+  if (cached) return cached;
+
+  const inFlightKey = `${ck}:${lang}`;
+  const existing = inFlight.get(inFlightKey);
+  if (existing) return existing;
+  const promise = _getWeatherImpl(lat, lng, date, lang);
+  inFlight.set(inFlightKey, promise);
+  try { return await promise; } finally { inFlight.delete(inFlightKey); }
+}
+
 // ── getDetailedWeather ──────────────────────────────────────────────────
 
-export async function getDetailedWeather(
+async function _getDetailedWeatherImpl(
   lat: string,
   lng: string,
   date: string,
@@ -434,6 +453,24 @@ export async function getDetailedWeather(
   return result;
 }
 
+export async function getDetailedWeather(
+  lat: string,
+  lng: string,
+  date: string,
+  lang: string,
+): Promise<WeatherResult> {
+  const ck = `detailed_${cacheKey(lat, lng, date)}`;
+  const cached = getCached(ck);
+  if (cached) return cached;
+
+  const inFlightKey = `${ck}:${lang}`;
+  const existing = inFlight.get(inFlightKey);
+  if (existing) return existing;
+  const promise = _getDetailedWeatherImpl(lat, lng, date, lang);
+  inFlight.set(inFlightKey, promise);
+  try { return await promise; } finally { inFlight.delete(inFlightKey); }
+}
+
 // ── ApiError ────────────────────────────────────────────────────────────
 
 export class ApiError extends Error {