Route layer merge through app core

docs/modernization/debt.md

@@ -49,7 +49,7 @@ agent or engineer to remove them without reconstructing context from chat.
 | DEBT-0029 | Open | Modernization | Image import route planning and execution dispatch now consume pure `pp_app_core` through the File menu, `pano_cli plan-image-import`, and the `DocumentImageImportServices` boundary, but the live adapter still loads images with legacy `Image`, calls legacy `Canvas::import_equirectangular`, or configures legacy import transform mode directly | Preserve current File > Import behavior while image import moves toward document/app/asset command services | `pp_app_core_document_import_tests`; `pano_cli plan-image-import --width 4096 --height 2048`; `pano_cli plan-image-import --width 1024 --height 1024`; `ctest --preset desktop-fast --build-config Debug` | Image loading, equirectangular import, transform-placement import, and failure reporting are owned by injected document/app/asset services with File-menu callbacks acting only as adapters and no legacy image-import adapter |
 | DEBT-0030 | Open | Modernization | File export menu action planning and execution dispatch now consume pure `pp_app_core` through the File menu, `pano_cli plan-export-menu`, and the `DocumentExportMenuServices` boundary, but the live adapter still opens legacy export dialogs and then reaches legacy canvas/render/video export code | Preserve current export menu behavior while export command execution moves toward document/app/renderer/video services | `pp_app_core_document_export_tests`; `pano_cli plan-export-menu --kind png`; `pano_cli plan-export-menu --kind animation-mp4 --demo`; `pano_cli plan-export-menu --kind layers --no-canvas`; `ctest --preset desktop-fast --build-config Debug` | Export menu routing, license gating, target creation, image/layer/cube/depth/animation/timelapse execution, and error reporting are owned by injected document/app/renderer/video services with File-menu callbacks acting only as UI adapters and no legacy export adapter |
 | DEBT-0031 | Open | Modernization | Top-level File menu command planning and execution dispatch now consume pure `pp_app_core` through `App::init_menu_file`, `pano_cli plan-file-menu`, and the `FileMenuServices` boundary, but the live adapter still invokes legacy dialogs, platform pickers, cloud code, share code, and canvas import/export paths directly | Preserve File menu behavior while app workflows move toward app/document/platform command services | `pp_app_core_file_menu_tests`; `pano_cli plan-file-menu --command save-as`; `pano_cli plan-file-menu --command import`; `pano_cli plan-file-menu --command cloud-upload`; `ctest --preset desktop-fast --build-config Debug` | File menu routing, picker dispatch, save/share/cloud/resize/export execution, and image/project import execution are owned by injected app/document/platform services with `App::init_menu_file` acting only as a UI adapter and no legacy File menu adapter |
-| DEBT-0032 | Open | Modernization | Layer menu command planning and execution dispatch now consume pure `pp_app_core` through `App::init_menu_layer`, `pano_cli plan-layer-menu`, and the `DocumentLayerMenuServices` boundary, and Layer menu clear now reuses the `DocumentCanvasClearServices` executor, but the live adapter still calls `App::dialog_layer_rename`, `NodePanelLayer::merge`, and reads `Canvas::I` animation/layer state directly | Preserve existing Layer menu behavior while layer commands move toward document/app services | `pp_app_core_document_layer_tests`; `pano_cli plan-layer-menu --command clear --current-index 1 --current-name Paint`; `pano_cli plan-layer-menu --command merge --current-index 2 --lower-name Paint`; `pano_cli plan-layer-menu --command rename --no-current-layer`; `ctest --preset desktop-fast --build-config Debug` | Layer rename, merge-down execution, animation gating, and selected-layer state are owned by injected document/app services with Layer-menu callbacks acting only as UI adapters and no legacy Layer menu adapter |
+| DEBT-0032 | Open | Modernization | Layer menu command planning and execution dispatch now consume pure `pp_app_core` through `App::init_menu_layer`, `pano_cli plan-layer-menu`, and the `DocumentLayerMenuServices` boundary, Layer menu clear reuses the `DocumentCanvasClearServices` executor, and Layer menu merge validates/dispatches through `DocumentLayerMergeServices`, but the live adapter still calls `App::dialog_layer_rename`, `NodePanelLayer::merge`, and reads `Canvas::I` animation/layer state directly | Preserve existing Layer menu behavior while layer commands move toward document/app services | `pp_app_core_document_layer_tests`; `pano_cli plan-layer-menu --command clear --current-index 1 --current-name Paint`; `pano_cli plan-layer-menu --command merge --current-index 2 --lower-name Paint`; `pano_cli plan-layer-merge --layer-count 3 --from-index 2 --to-index 1`; `pano_cli plan-layer-merge --layer-count 3 --from-index 2 --to-index 1 --animation-duration 3`; `pano_cli plan-layer-menu --command rename --no-current-layer`; `ctest --preset desktop-fast --build-config Debug` | Layer rename, merge-down execution, animation gating, and selected-layer state are owned by injected document/app services with Layer-menu callbacks acting only as UI adapters and no legacy Layer menu adapter |
 | DEBT-0033 | Open | Modernization | Tools menu planning and direct command execution dispatch now consume pure `pp_app_core` through `App::init_menu_tools`, `pano_cli plan-tools-menu`, `pano_cli plan-tools-panel`, and the `ToolsMenuServices` boundary, but live adapters still construct legacy `NodePanelFloating` panels, mutate legacy panel nodes, clear `CanvasModeGrid`, reset `NodeCanvas` camera state, open legacy shortcuts UI, and call the iOS SonarPen bridge directly | Preserve current Tools menu behavior while UI shell actions move toward app/UI/platform services | `pp_app_core_tools_menu_tests`; `pano_cli plan-tools-menu --command shortcuts`; `pano_cli plan-tools-panel --panel layers`; `pano_cli plan-tools-panel --panel animation --already-visible`; `ctest --preset desktop-fast --build-config Debug` | Tools panel creation, submenu routing, grid clear, camera reset, shortcuts dialog, and SonarPen dispatch are owned by injected app/UI/platform services with `App::init_menu_tools` acting only as a UI adapter and no legacy Tools adapter |
 | DEBT-0034 | Open | Modernization | About menu command planning and execution dispatch now consume pure `pp_app_core` through `App::init_menu_about`, `pano_cli plan-about-menu`, and the `AboutMenuServices` boundary, but the live adapter still opens legacy About/manual/what's-new dialogs, invokes the injected crash hook, and runs the legacy Canvas stroke performance test directly | Preserve About menu behavior while dialogs and diagnostics move toward app/UI/platform services | `pp_app_core_about_menu_tests`; `pano_cli plan-about-menu --command news --version-major 2 --version-minor 5 --version-fix 7`; `pano_cli plan-about-menu --command performance --no-canvas`; `ctest --preset desktop-fast --build-config Debug` | About/manual/what's-new dialog dispatch, crash-test dispatch, and performance-test execution are owned by injected app/UI/platform services with `App::init_menu_about` acting only as a UI adapter and no legacy About adapter |
 | DEBT-0035 | Open | Modernization | Main toolbar/status command planning and execution dispatch now consume pure `pp_app_core` through `App::init_toolbar_main`, `pano_cli plan-main-toolbar`, and the `MainToolbarServices` boundary, and history/canvas commands now hand off through `HistoryUiServices` and `DocumentCanvasClearServices`, but the live adapter still opens legacy open/save/settings/message-box dialogs and delegates to legacy history/canvas adapters | Preserve reachable toolbar/status behavior while app shell commands move toward app/document/UI services | `pp_app_core_main_toolbar_tests`; `pano_cli plan-main-toolbar --command undo --undo-count 2`; `pano_cli plan-main-toolbar --command clear-canvas --no-canvas`; `ctest --preset desktop-fast --build-config Debug` | Open/save/settings/message-box routing, undo/redo/clear-history execution, and canvas-clear execution are owned by injected app/document/UI services with `App::init_toolbar_main` acting only as a UI adapter and no legacy toolbar adapter |

docs/modernization/roadmap.md

@@ -501,6 +501,8 @@ rename, and merge-down labels/actions, and direct Layer menu commands now
 dispatch through `DocumentLayerMenuServices` before the legacy canvas/layer UI
 adapter continues execution. Layer menu clear now routes through the shared
 `DocumentCanvasClearServices` executor before the legacy canvas-clear adapter
+continues, and Layer menu merge now validates and dispatches through
+`DocumentLayerMergeServices` before the legacy layer-panel merge adapter
 continues.
 `pano_cli plan-animation-operation` exposes app-core planning for animation
 frame add, duplicate, remove, duration adjustment, timeline moves, timeline
@@ -1249,8 +1251,9 @@ Results:
   layer operation side-effect dispatch, no-op operation preservation,
   malformed operation rejection, Layer menu labels/actions, merge-down routing,
   animated merge blocking, missing selection handling, bad Layer menu state
-  rejection, Layer menu executor dispatch, and no-op menu execution
-  preservation.
+  rejection, Layer menu executor dispatch, no-op menu execution preservation,
+  merge-plan validation, unsupported animated merge rejection, merge executor
+  dispatch, and malformed merge-plan rejection.
 - `pano_cli_plan_layer_rename_smoke`,
   `pano_cli_plan_layer_rename_no_op_smoke`, and
   `pano_cli_plan_layer_rename_rejects_empty_name` passed and expose live
@@ -1261,6 +1264,9 @@ Results:
   `pano_cli_plan_layer_menu_missing_selection_smoke`, and
   `pano_cli_plan_layer_menu_rejects_bad_state` passed and expose live Layer
   menu planning as JSON automation.
+- `pano_cli_plan_layer_merge_smoke` and
+  `pano_cli_plan_layer_merge_animated_rejected` passed and expose live
+  merge execution planning as JSON automation.
 - `pano_cli_plan_layer_operation_add_smoke`,
   `pano_cli_plan_layer_operation_reorder_no_op_smoke`,
   `pano_cli_plan_layer_operation_highlight_smoke`, and