probes: print cells and column weights; split-row ruler label

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/ui.cpp

@@ -1826,7 +1826,13 @@ void rebuild_cursors_pane(App& app) {
     for (int r = 0; r < app.rows->row_count(); ++r) {
       if (!rulers) break;
       char who[64];
-      std::snprintf(who, sizeof(who), "row %d", r);
+      // A row split into cells names its plots the way the rest of the UI does ("plot 2a"); an
+      // unsplit row keeps the wording it always had.
+      if (app.rows->cells_in_row(app.rows->figure_row_of(r)) > 1) {
+        std::snprintf(who, sizeof(who), "plot %s", app.rows->plot_label(r).c_str());
+      } else {
+        std::snprintf(who, sizeof(who), "row %d", r);
+      }
       app.cursors_lines.push_back(cursors_line(app, who, plot::Color::hex(0), false));
       app.cursors_lines.back().row = r;
       app.cursors_lines.back().slot = -1;
@@ -7011,6 +7017,10 @@ int run_ui(int argc, char** argv, const Config& cfg, ScopeModel& model, Acquisit
       }
       std::printf("]");
     }
+    // The split, appended so every field before it keeps its place: cells per figure row, and the
+    // cell weights per figure row (`|` between rows, empty for an unsplit one). RowSet only.
+    std::printf(" cells=[%s] colweights=[%s]", layout_cells_text(rows).c_str(),
+                layout_colweights_text(rows).c_str());
     std::printf("\n");
     for (int r = 0; r < rows.row_count() && r < RowSet::kMaxRows; ++r) {
       for (int s = 0; s < RowSet::kSlotsPerRow; ++s) {