Prepare renderer snapshots before legacy exports

docs/modernization/roadmap.md

@@ -680,6 +680,10 @@ document-frame compositor and renderer-neutral recording upload path, reporting
 texture, transition, byte, payload, and command counts. Live save writer
 replacement, export adoption, and renderer-owned readback remain under
 `DEBT-0010`/`DEBT-0013`/`DEBT-0036`.
+Live equirectangular, layer, animation-frame, and cube-face export adapters now
+prepare the same payload-bearing document snapshot and renderer-neutral upload
+report before delegating to retained `Canvas` export execution, so export
+workflows consume the boundary without changing file output yet.
 `pano_cli plan-image-import` exposes app-core planning for File > Import image
 route decisions, including wide equirectangular images, legacy vertical cube
 strips, regular transform-placement images, and invalid image dimensions; live
@@ -2226,6 +2230,10 @@ Results:
   frame through `pp_paint_renderer::upload_document_frame_faces` and the
   `RecordingRenderDevice`, emitting `rendererUpload` JSON with texture,
   transition, command, byte, and active-frame payload counts.
+- Live equirectangular, layer, animation-frame, and cube-face export bridges now
+  capture the payload-bearing canvas document snapshot and run the
+  renderer-neutral upload report before retained `Canvas` export execution;
+  failures are logged and retained export still continues to preserve behavior.
 - `pp_app_core_document_import_tests` passed, covering wide equirectangular,
   legacy vertical cube strip, regular transform-placement, and invalid-dimension
   import route decisions, equirectangular service dispatch, transform import
@@ -2509,6 +2517,10 @@ Results:
   snapshot through the pure document-frame compositor and renderer-neutral
   texture upload stream, so agents can validate document/canvas payloads moving
   into renderer commands before live canvas export/save writer replacement.
+- Live image/collection/cube export adapters now prepare and log the same
+  document/canvas plus renderer-upload readiness before retained `Canvas`
+  export calls. Depth and video export remain on their prior retained paths;
+  actual image/cube writer replacement remains tracked under export debt.
 - Snapshot creation now rejects invalid embedded RGBA8 face payloads before
   document export or history can persist malformed state.
 - Package-smoke wrappers validate the Windows CMake app executable/runtime