feat(windows): sync desktop pet glow with active theme

[TokinoChanshi]

Summary

• recognize only the exact app://codex/avatar-overlay desktop-pet renderer
• keep official pet assets, animation, interaction, and window transparency intact
• apply a theme-derived accent glow that refreshes with live theme changes
• add pet.mode: accent | off and pet.glow configuration
• extend cleanup, verification, and regression coverage

Validation

• node --check windows/scripts/injector.mjs
• node --check windows/assets/renderer-inject.js
• all windows/tests/*.mjs tests passed
• injector --self-test passed
• payload validation passed
• git diff --check passed

Live Windows pet visual signoff remains pending.

[Fei-Away]

Thanks for the contribution! We just merged #216, unifying the macOS/Windows skin runtime into a single source (runtime/ + tools/selectors.json, attribute-driven rendering) — it rewrote the files this PR touches, so it's no longer compatible as submitted. Closing for now; a fresh PR against the new runtime would be very welcome if the idea still applies. Thanks again for the time you put into this!

感谢贡献！我们刚合并了 #216，把双端换肤 runtime 统一成了单一源码（runtime/ + tools/selectors.json，属性驱动渲染），这个 PR 改动的文件已经被那次重构重写，现在不再适用。先关闭，如果思路还有价值，非常欢迎基于新架构重新提一个 PR。谢谢你花的时间！