Extract grid UI operation planning

docs/modernization/roadmap.md

@@ -499,6 +499,10 @@ before legacy `Canvas`/`Layer` frame execution continues.
 changes, tip/pattern/dual texture changes, preset brush replacement, and stroke
 settings refreshes used by the live brush, quick, color, and floating panel
 callbacks before legacy `Brush` mutation and resource loading continue.
+`pano_cli plan-grid-operation` exposes app-core planning for grid heightmap
+pick/load/reload/clear, lightmap render capability/limit checks, and heightmap
+commit used by the live grid panel before legacy image loading, OpenGL texture
+updates, nanort lightmap baking, and `Canvas::draw_objects` execution continue.
 `pp_platform_api` now owns a headless `PlatformServices` interface for
 startup storage path preparation, clipboard text, cursor visibility,
 virtual-keyboard visibility, UI-thread lifecycle hooks, render-context
@@ -1137,6 +1141,16 @@ Results:
   `pano_cli_plan_brush_operation_rejects_bad_color`, and
   `pano_cli_plan_brush_operation_rejects_empty_texture` passed and expose live
   brush/color/preset UI planning as JSON automation.
+- `pp_app_core_grid_ui_tests` passed, covering heightmap pick/load/reload/clear
+  planning, lightmap capability and limit checks, missing-heightmap no-op
+  behavior, and commit canvas gating.
+- `pano_cli_plan_grid_operation_pick_smoke`,
+  `pano_cli_plan_grid_operation_load_smoke`,
+  `pano_cli_plan_grid_operation_render_supported_smoke`,
+  `pano_cli_plan_grid_operation_render_unsupported_smoke`,
+  `pano_cli_plan_grid_operation_rejects_empty_reload`, and
+  `pano_cli_plan_grid_operation_rejects_bad_samples` passed and expose live
+  grid/heightmap/lightmap planning as JSON automation.
 - `pp_app_core_document_sharing_tests` passed, covering saved-path gating before
   platform share execution.
 - `pano_cli_plan_share_file_unsaved_smoke` and