wallpaper-engine-renderer

wallpaper-engine-renderer is a session-oriented wallpaper runtime that is being refactored from a scene-centric renderer into:

WallpaperSession -> ContentBackend -> Output

Current status:

• WallpaperSession is the top-level API surface.
• scene is one backend, not the architectural center.
• render is responsible for how frames are drawn.
• output is responsible for where frames are presented.
• host provides platform capabilities to the runtime and backends.
• current architecture notes live in wpdoc/runtime-architecture.md.

The existing scene pipeline is still used internally through a scene backend engine shim while the runtime contracts are being lifted to the top level.

Validation commands:

cmake -S . -B build-check -DBUILD_TESTING=ON
cmake --build build-check -j2
ctest --test-dir build-check --output-on-failure
cmake --build build-check -j2 --target sceneviewer