Plan picked path callbacks in app core

docs/modernization/roadmap.md

@@ -451,6 +451,9 @@ PBO readback, and MP4 encoder execution continue.
 `pano_cli plan-share-file` exposes the app-core saved-path decision used by the
 live platform share command before iOS/macOS sharing bridges or retained no-op
 platform branches execute.
+`pano_cli plan-picked-path` exposes the app-core selected-path decision used by
+live image, file, save-file, and directory picker branches before retained
+platform callbacks or legacy picker bridges continue.
 `pano_cli plan-cloud-upload` exposes the app-core cloud upload decision used by
 the live cloud upload command for missing-canvas, new-document warning, publish
 prompt, and dirty-document save-before-upload states before legacy UI, canvas,
@@ -937,6 +940,12 @@ Results:
 - `pano_cli_plan_share_file_unsaved_smoke` and
   `pano_cli_plan_share_file_saved_smoke` passed and expose app-core share
   decisions as JSON.
+- `pp_app_core_document_platform_io_tests` passed, covering empty selected-path
+  filtering and non-empty picked-path callback planning before platform picker
+  callbacks.
+- `pano_cli_plan_picked_path_empty_smoke` and
+  `pano_cli_plan_picked_path_selected_smoke` passed and expose app-core picker
+  selected-path decisions as JSON.
 - `panopainter_validate_shaders` passed, validating 25 shader programs and 7
   shader includes for stage markers and include graph integrity.
 - `pp_renderer_gl_capabilities_tests` passed on default MSVC, vcpkg-headless,