Own Live2D renderer

What it was. The plugin's own desktop window: a transparent, always-on-top, click-through frame holding a PixiJS Live2D engine — the maintained ones take Cubism 2 through 5 models on PixiJS 8 and drive the mouth from an audio buffer — fed the clip the synthesizer already makes, with the Cubism core loaded from Live2D's own CDN at run time, since it is proprietary rather than ours to ship: Live2D's licence is free to develop against, and free to release on for an individual under the small-scale exemption from its SDK Release License, but the core itself is theirs to distribute. It is the shape the open-source companions for coding agents take, each with its renderer, its tray icon and its build.

Why deferred. The window exists already. Live2DViewerEX is on the desktop with the person's models loaded, it is transparent and on top and over every app, and its socket takes a bubble, a sound, a motion and an expression and returns a tap — everything the viewer as the stage needs and nothing it would build. A renderer of our own is a second surface to keep working as PixiJS, the Cubism SDK and the packaging tool each move under it, against a viewer that someone else keeps working, and the interface's rule is one plugin and nothing that has to be re-implemented when the platform moves.

Revisit when: the viewer's socket cannot do something the stage needs — a sound played on the model without its mouth moving, a bubble that cannot hold what a line needs, no event for something the stage must react to — or the plugin runs where the viewer does not, since the viewer runs on Windows and on phones and the plugin runs wherever node does. Either is a fact one probe or one install states, and the proposal that then follows renders in a window what the viewer sink already sends.

Cheaper interim: the viewer sink, and where no viewer runs, the reading through the stock player as today.