feat(tours): assistant takes found places into saved tours and route files from the chat

P6: insert_tour_stop and remove_tour_stop take a place into a saved hike or
city walk as one stop and out again, each the other's undo, with change
cards in the chat. The planner's insertion rule (poiInsertion) moved to
shared so the planner and the server place a stop the same way. "+ Tour" on
a found place holds it as a stop of the saved tour open in the planner.

P7: GPX, KML and KMZ files attached in the chat are read into their tracks
and each is held as a change that takes it in as a hike through
import_tour_gpx, undoable per track; the GPX text stays on the held call.

client/src/api/assistant.ts

@@ -18,6 +18,7 @@ import {
   type AssistantChatRequest,
   type AssistantDecisionsRequest,
   type AssistantErrorCode,
+  type AssistantInsertFoundPlaceRequest,
   type AssistantRenderUploadResponse,
   type AssistantScope,
   type AssistantShareRequest,
@@ -143,6 +144,13 @@ export const assistantApi = {
     body: AssistantAddFoundPlaceRequest
   ): Promise<AssistantAddFoundPlaceResponse> =>
     apiClient.post(`${tripBase(tripId)}/threads/${threadId}/found-places`, body).then((r) => r.data),
+  // "+ Tour": a found place taken into the saved tour open in the planner, held as a change like "+ Day 3".
+  insertFoundPlace: (
+    tripId: number,
+    threadId: number,
+    body: AssistantInsertFoundPlaceRequest
+  ): Promise<AssistantAddFoundPlaceResponse> =>
+    apiClient.post(`${tripBase(tripId)}/threads/${threadId}/found-places/tour`, body).then((r) => r.data),
   // A proposal an answer showed as a card ("Plan this"): answers like a found place, with the message holding it.
   takeProposal: (
     tripId: number,