Sync the Fly App's waypoint routes through the API Server

Routes saved in the Fly App's mission library now sync to a new per-user
routes collection on the API Server, in the WaypointMissionSpec JSON
format. The library pulls on load and pushes on every save and delete,
merges last-writer-wins by updatedAt, keeps unacknowledged deletes as
tombstones, and keeps working offline. Each signed-in account has its
own copy on the device; routes saved while signed out go to the first
account that signs in.

The API Server gets list / get / upsert / delete route endpoints with a
PocketBase migration, and the Web App a read-only Routes view on the
dashboard (rebuilt dist).

Tested against a fake PocketBase and a fake server only; not yet tried
with a real sign-in on the tablet.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Web App/server/main.go

@@ -88,6 +88,9 @@ func main() {
 	mux.HandleFunc("PATCH /bff/flights/{id}", app.requireAuth(app.handleUpdateFlight))
 	mux.HandleFunc("DELETE /bff/flights/{id}", app.requireAuth(app.handleDeleteFlight))
 	mux.HandleFunc("GET /bff/logbook/export", app.requireAuth(app.handleExportLogbook))
+	// Routes — saved waypoint missions from the Fly App (read-only here)
+	mux.HandleFunc("GET /bff/routes", app.requireAuth(app.handleListRoutes))
+
 	// Documents — the compliance + operational document store (scoping upstream)
 	mux.HandleFunc("GET /bff/documents", app.requireAuth(app.handleListDocuments))
 	mux.HandleFunc("POST /bff/documents", app.requireAuth(app.handleCreateDocument))