feat(collections): bulk-add selected trip places to a list (#1081)

Add a "Save to collection" action to the trip place list's selection bar (next to
bulk category + delete): it opens a list picker and copies every selected place
into the chosen list in one request, instead of one-by-one from each place.

- Server: saveFromTripPlaces (one access check + one WS notify), POST
  places/from-trip-many; dedups by name/coords, skips missing ids, honours force.
- Client: saveFromTripMany api + SaveTripPlacesToListModal; the selection-bar
  button is gated on the collections addon being enabled.
- Copy count / skipped-duplicates toast; strings in all 22 locales.
- Service + controller tests for the bulk path.

client/src/api/collections.ts

@@ -63,6 +63,8 @@ export const collectionsApi = {
     ax.post(`${base}/places`, body satisfies CollectionSavePlaceRequest).then((r: AxiosResponse) => r.data),
   saveFromTrip: (body: CollectionSaveFromTripRequest): Promise<CollectionSaveResult> =>
     ax.post(`${base}/places/from-trip`, body satisfies CollectionSaveFromTripRequest).then((r: AxiosResponse) => r.data),
+  saveFromTripMany: (collectionId: number, tripId: number, placeIds: number[], force?: boolean): Promise<{ copied: number; skipped: { id: number; name: string }[] }> =>
+    ax.post(`${base}/places/from-trip-many`, { collection_id: collectionId, source_trip_id: tripId, source_place_ids: placeIds, force }).then((r: AxiosResponse) => r.data),
   updatePlace: (pid: number, body: CollectionPlaceUpdateRequest): Promise<CollectionPlace> =>
     ax.patch(`${base}/places/${pid}`, body satisfies CollectionPlaceUpdateRequest).then((r: AxiosResponse) => r.data),
   setStatus: (pid: number, status: CollectionStatus): Promise<CollectionPlace> =>