## Description
Adds the Godot Stage rim light pipeline and development observation
tooling.
- Replaces the old avatar glow-only compositor path with a staged
post-process compositor.
- Adds avatar-scoped edge light, glow, material overlay, and final
colour mapping stages.
- Implements a dev observation adapter for exporting
viewport/render-stage artefacts.
- Adds visual verification tooling and baseline docs for Godot Stage
rendering work.
- Documents the technical art workflow and rendering effect behaviour.
Lilia_Chen
7c45aa86bc