feat(lists): drag tasks and list entries onto another list; remember open list and view; live pill in lists

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

internal/api/server.go

@@ -263,6 +263,7 @@ func (s *Server) Router() http.Handler {
 		r.Patch("/api/v1/lists/{id}/items/{itemId}", s.handleToggleListItem)
 		r.Put("/api/v1/lists/{id}/items/{itemId}", s.handleUpdateListItem)
 		r.Delete("/api/v1/lists/{id}/items/{itemId}", s.handleDeleteListItem)
+		r.Post("/api/v1/lists/{id}/items/{itemId}/move", s.handleMoveListItem)
 		r.Post("/api/v1/lists/{id}/items/reorder", s.handleReorderListItems)
 		r.Put("/api/v1/lists/{id}/items/reorder", s.handleReorderListItems)
 		r.Post("/api/v1/lists/{id}/clear-completed", s.handleClearCompletedItems)