Export layer collections through paint renderer

docs/modernization/build-inventory.md

@@ -258,7 +258,9 @@ powershell -ExecutionPolicy Bypass -File scripts\automation\apple-remote-build.p
   pure six-face PNG export bytes encoded through `pp_assets`. The compositor
   tests now also cover equirectangular PNG export from that same composited
   document frame using the shader-equivalent cube sampling policy and
-  `pp_assets` PNG encoding.
+  `pp_assets` PNG encoding, independent layer equirectangular PNG export for
+  layer collections, and merged animation-frame equirectangular PNG export for
+  frame collections.
 - `pano_cli simulate-document-export` exposes the same pure document-to-PPI
   export, asset-level decode, and document reimport path through JSON
   automation and is covered by `pano_cli_simulate_document_export_smoke`.
@@ -289,7 +291,10 @@ powershell -ExecutionPolicy Bypass -File scripts\automation\apple-remote-build.p
   falls back to `Canvas::export_cube_faces` if snapshot capture, PNG generation,
   or file writing fails. PNG equirectangular export writes a pure
   document/paint-renderer equirectangular PNG before falling back to the
-  retained writer; JPEG/XMP equirectangular export, layer, animation-frame,
+  retained writer. Payload-complete layer and animation-frame PNG collections
+  write pure document/paint-renderer equirectangular PNG sequences through the
+  app-core collection write/publish executor before retained fallback; JPEG/XMP
+  equirectangular export, Web handoff, incomplete-readback collection cases,
   depth, and video export remain on retained writer paths.
 - `pano_cli save-document-project` writes that pure document export to a PPI
   file and is covered by `pano_cli_save_document_project_roundtrip_smoke`,
@@ -1134,8 +1139,11 @@ powershell -ExecutionPolicy Bypass -File scripts\automation\apple-remote-build.p
   app-core planned legacy work-directory face paths through the app-core
   write/publish executor before falling back to the retained writer, PNG
   equirectangular export writes the pure document/paint-renderer
-  equirectangular PNG before retained fallback, and JPEG/XMP, collection, and
-  depth exports remain on older retained paths. It
+  equirectangular PNG before retained fallback, payload-complete layer and
+  animation-frame collections write pure document/paint-renderer PNG sequences
+  through the app-core collection write/publish executor, and JPEG/XMP,
+  Web/incomplete-readback collection cases, and depth exports remain on older
+  retained paths. It
   also bridges timelapse and animation MP4 export picker-selected paths while
   preserving desktop worker-thread timelapse behavior, mobile/Web save
   callbacks, `App::rec_export`, animation `Canvas::export_anim_mp4`, and

docs/modernization/capability-map.md

@@ -24,8 +24,8 @@ and validation command.
 | Capability | Current Area | Target Owner | Required Tests |
 | --- | --- | --- | --- |
 | PNG/JPEG import | `Image`, `Canvas` import paths | `pp_assets`, `pp_document` | Fixture import, malformed file |
-| PNG/JPEG export | `Canvas`, `Image`, export dialogs | `pp_assets`, `pp_paint_renderer`, `pp_app_core` | Golden output tolerance, export start/target planning tests, live export-adapter document snapshot readiness through the shared paint-renderer export report, pure cube-face PNG writer, pure equirectangular PNG writer, JPEG/XMP parity still retained |
-| Equirectangular import/export | `Canvas`, shaders, RTT, export dialogs | `pp_paint_renderer`, `pp_app_core` | Tiny cube/equirect golden, app-core file target tests, live export-adapter renderer-upload/face-PNG readiness report, pure document-frame equirectangular PNG export and live PNG writer fallback, JPEG/XMP retained until metadata parity is owned |
+| PNG/JPEG export | `Canvas`, `Image`, export dialogs | `pp_assets`, `pp_paint_renderer`, `pp_app_core` | Golden output tolerance, export start/target planning tests, live export-adapter document snapshot readiness through the shared paint-renderer export report, pure cube-face PNG writer, pure equirectangular PNG writer, pure layer/frame collection PNG writers, app-core collection write executor, JPEG/XMP parity still retained |
+| Equirectangular import/export | `Canvas`, shaders, RTT, export dialogs | `pp_paint_renderer`, `pp_app_core` | Tiny cube/equirect golden, app-core file target tests, live export-adapter renderer-upload/face-PNG readiness report, pure document-frame equirectangular PNG export and live PNG writer fallback, pure layer/frame equirectangular PNG collection export, JPEG/XMP retained until metadata parity is owned |
 | Cube face export | `Canvas` fallback | `pp_paint_renderer`, `pp_app_core` | Pure six-face document frame composite, renderer texture-upload bridge, shared export-readiness report, app-core face filename planning and write/publish service execution, payload-complete canvas-snapshot renderer-upload and face-PNG automation, live document/renderer face-PNG writer with retained Canvas fallback, OpenGL command-plan coverage, six-face golden set |
 | Depth export | `Canvas`, grid tools | `pp_paint_renderer` | Float/readback validation |
 

docs/modernization/roadmap.md

@@ -692,9 +692,12 @@ executor using the app-core-planned legacy face filenames when available and
 falls back to retained `Canvas::export_cube_faces` on snapshot/write failure.
 PNG equirectangular export now uses the same document/composite payload to
 generate an equirectangular PNG through `pp_paint_renderer` before the retained
-fallback. JPEG/XMP equirectangular export, layer collections, animation-frame
-collections, depth, and video still delegate to retained `Canvas` writers after
-readiness reporting.
+fallback. Payload-complete layer and animation-frame PNG collections now use
+pure `pp_paint_renderer` equirectangular PNG generation plus app-core
+collection write/publish execution before retained fallback. JPEG/XMP
+equirectangular export, Web handoff, depth, video, and incomplete-readback
+collection cases still delegate to retained `Canvas` writers after readiness
+reporting.
 `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
@@ -2536,10 +2539,13 @@ Results:
   write/publish service executor before falling back to retained `Canvas`
   execution on failure. PNG equirectangular export now writes a
   `pp_paint_renderer` equirectangular PNG from the same composited document
-  frame before falling back to retained `Canvas` execution; JPEG/XMP,
-  layer, animation-frame, depth, and video export remain on their prior
-  retained writer paths. Actual broader writer replacement remains tracked
-  under export debt.
+  frame before falling back to retained `Canvas` execution; payload-complete
+  layer and animation-frame PNG collections now write pure
+  `pp_paint_renderer` equirectangular PNG sequences through a tested app-core
+  collection write/publish executor before retained fallback. JPEG/XMP,
+  Web prepared-file handoff, depth, video, and incomplete-readback collection
+  cases remain on their prior retained writer paths. Actual broader 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