Add explicit PPI project writer

docs/modernization/build-inventory.md

@@ -120,11 +120,12 @@ Known local toolchain state:
   frame counts, durations, and decoded face-pixel payloads when present; the
   metadata-only minimal fixture remains covered by
   `pano_cli_load_project_metadata_smoke`.
-- `pano_cli save-project` writes generated multi-layer, multi-frame PPI files
-  with configurable layer opacity, blend mode, alpha lock, and visibility
-  through `pp_assets`; test dirty-face payloads can target explicit generated
-  layer/frame slots. It is covered by `pano_cli_save_project_roundtrip_smoke`
-  and `pano_cli_save_project_payload_roundtrip_smoke`, which reload generated
+- `pp_assets::create_ppi_project` writes generated multi-layer, multi-frame
+  PPI files with explicit per-layer names, opacity, blend mode, alpha lock,
+  visibility, per-layer frame durations, and targeted dirty-face layer/frame
+  payloads. `pano_cli save-project` exposes that path for automation and is
+  covered by `pano_cli_save_project_roundtrip_smoke` and
+  `pano_cli_save_project_payload_roundtrip_smoke`, which reload generated
   metadata-only and targeted dirty-face-payload projects through
   `pano_cli load-project`.
 - `pano_cli create-document` supports `--frames` and `--frame-duration-ms` and

docs/modernization/debt.md

@@ -31,7 +31,7 @@ agent or engineer to remove them without reconstructing context from chat.
 | DEBT-0010 | Open | Modernization | `pp_document` is a pure layer/frame/document/undo-history model with alpha-lock metadata, snapshot construction, per-layer frame metadata, renderer-free RGBA8 face payload storage, and renderer-free alpha8 selection-mask storage, but it is not yet wired to legacy `Canvas`, save, or legacy action commands | Keep extraction incremental while preserving app behavior | `ctest --preset desktop-fast --build-config Debug`; `pano_cli create-document --width 64 --height 32 --layers 2`; `pano_cli load-project --path tests\data\projects\minimal-project.ppi`; `pp_document_ppi_import_tests`; `pano_cli_simulate_document_edits_smoke` | Legacy document behavior is represented by `pp_document` tests and the app consumes it through a boundary/facade |
 | DEBT-0011 | Open | Modernization | `package-smoke` validates the Windows CMake app artifact only, not AppX/APK/Apple/WebGL package outputs | Platform package targets are not migrated to root CMake yet | `powershell -ExecutionPolicy Bypass -File scripts\automation\package-smoke.ps1 -Preset windows-msvc-default -Configuration Debug` | Package-smoke covers Windows AppX, Android APK variants, Apple bundles, and WebGL output where local toolchains are present |
 | DEBT-0012 | Open | Modernization | `pp_ui_core` uses vcpkg tinyxml2 on `windows-msvc-vcpkg-headless`, but retains `pp_vendor_tinyxml2` for default and unproven platform presets | Mobile/AppX/Apple triplets and app packaging still need validation before removing the vendored fallback | `ctest --preset desktop-fast-vcpkg --build-config Debug`; `ctest --preset desktop-fast --build-config Debug`; `powershell -ExecutionPolicy Bypass -File scripts\automation\platform-build.ps1 -Presets android-arm64` | All supported presets consume vcpkg tinyxml2 or document a permanent vendored exception |
-| DEBT-0013 | Open | Modernization | `pp_assets`, `pano_cli inspect-project`, `pano_cli load-project`, and `pano_cli save-project` validate the fixed PPI header, thumbnail/body byte layout, generated multi-layer/multi-frame PPI writing with layer opacity/blend/alpha-lock/visibility metadata, metadata-only and targeted dirty-face-payload save/load round-trips, layer/frame index, dirty-face descriptors, dirty-face PNG payload metadata, asset-level RGBA PNG payload decoding, and decoded pixel attachment to `pp_document`, but full legacy PPI round-trip parity is not yet extracted | Full PPI save parity requires staged extraction of legacy `Canvas` serialization and image/layer payload handling | `ctest --preset desktop-fast --build-config Debug`; `pp_assets_image_pixels_tests`; `pp_assets_ppi_header_tests`; `pp_document_ppi_import_tests`; `pano_cli_inspect_project_layout_smoke`; `pano_cli_load_project_metadata_smoke`; `pano_cli_save_project_roundtrip_smoke`; `pano_cli_save_project_payload_roundtrip_smoke` | Full PPI load/save fixtures cover thumbnails, decoded layer face payloads attached to documents, frames, corrupt payloads, dirty-face payload saving, arbitrary legacy canvas payload/layout combinations, and legacy app round-trip compatibility |
+| DEBT-0013 | Open | Modernization | `pp_assets`, `pano_cli inspect-project`, `pano_cli load-project`, and `pano_cli save-project` validate the fixed PPI header, thumbnail/body byte layout, generated multi-layer/multi-frame PPI writing with explicit layer opacity/blend/alpha-lock/visibility metadata, per-layer frame durations, metadata-only and targeted dirty-face-payload save/load round-trips, layer/frame index, dirty-face descriptors, dirty-face PNG payload metadata, asset-level RGBA PNG payload decoding, and decoded pixel attachment to `pp_document`, but full legacy PPI round-trip parity is not yet extracted | Full PPI save parity requires staged extraction of legacy `Canvas` serialization and image/layer payload handling | `ctest --preset desktop-fast --build-config Debug`; `pp_assets_image_pixels_tests`; `pp_assets_ppi_header_tests`; `pp_document_ppi_import_tests`; `pano_cli_inspect_project_layout_smoke`; `pano_cli_load_project_metadata_smoke`; `pano_cli_save_project_roundtrip_smoke`; `pano_cli_save_project_payload_roundtrip_smoke` | Full PPI load/save fixtures cover thumbnails, decoded layer face payloads attached to documents, frames, corrupt payloads, dirty-face payload saving, arbitrary legacy canvas payload/layout combinations, and legacy app round-trip compatibility |
 | DEBT-0014 | Open | Modernization | `windows-clangcl-asan` now configures as a headless Ninja/clang-cl preset and uses the release MSVC runtime required by ASan, but local builds still fail because installed clang-cl 18.1.8 is paired with VS 2026-preview STL headers that require Clang 20 or newer | Sanitizer validation should be local and repeatable, but this machine's compiler/header pairing is incompatible | `cmake --fresh --preset windows-clangcl-asan`; `cmake --build --preset windows-clangcl-asan --target pp_foundation` | Install/use Clang 20+ with the VS 2026 STL, or point the preset at a compatible VS 2022 toolchain, then make `platform-build.ps1 -Presets windows-clangcl-asan` pass for the headless matrix |
 
 ## Closed Debt

docs/modernization/roadmap.md

@@ -344,11 +344,11 @@ asset-level decode coverage, and
 `pano_cli load-project` creates a `pp_document` projection with per-layer frame
 counts, durations, and decoded face-pixel payload attachment when PPI image
 payloads are present.
-`pano_cli save-project` writes generated multi-layer, multi-frame PPI files
-with layer opacity, blend mode, alpha lock, and visibility metadata through the
-extracted `pp_assets` writer and round-trips metadata-only and test
-dirty-face-payload variants through `load-project`; dirty-face payloads can be
-targeted to explicit generated layer/frame slots for animation coverage.
+`pp_assets` can write generated PPI projects with explicit per-layer names,
+visibility, opacity, blend mode, alpha lock, per-layer frame durations, and
+dirty-face payloads targeted to layer/frame/face slots. `pano_cli save-project`
+exposes the generated writer for metadata-only and test dirty-face-payload
+round-trips through `load-project`.
 `pano_cli create-document` can create simple animation documents with explicit
 frame count/duration. `pano_cli simulate-document-edits` exercises pure
 layer metadata, frame reordering, active-index preservation, tiny face-payload
@@ -680,9 +680,10 @@ Results:
 - `pp_assets_image_pixels_tests` passed, including RGBA8 PNG decode and corrupt
   payload rejection.
 - `pp_assets_ppi_header_tests` passed, including PPI thumbnail/body layout,
-  body summary validation, layer/frame indexing, dirty-face PNG payload
-  metadata validation, targeted layer/frame dirty-face writing, and decoded
-  dirty-face payload coverage.
+  body summary validation, layer/frame indexing, explicit per-layer metadata
+  and per-layer frame duration writing, dirty-face PNG payload metadata
+  validation, targeted layer/frame dirty-face writing, and decoded dirty-face
+  payload coverage.
 - `pp_assets_settings_document_tests` passed.
 - `pp_paint_brush_tests` passed.
 - `pp_paint_blend_tests` passed.
@@ -801,6 +802,8 @@ Results:
   through JSON automation and is covered by metadata-only and
   dirty-face-payload save/load round-trip smoke tests. Full legacy canvas save
   parity remains tracked by DEBT-0013.
+- `pp_assets::create_ppi_project` exposes the underlying generated PPI writer
+  for non-uniform layer metadata and frame-duration extraction work.
 - PowerShell package-smoke wrapper validates the Windows CMake app executable
   and runtime `data/` copy.
 - Android arm64 configured with NDK 29.0.14206865 through the platform-build