## Summary / 摘要
- Fully revert the production behavior, contracts, documentation, and
frame-preparation changes introduced by PR #58.
- Restore the previous fully opaque flat-chroma source workflow and its
bounded transparency, edge-repair, and QA pipeline for Maker and Studio
production.
- Rewrite the existing unreleased native-Alpha-default changelog
fragment so the eventual release notes contain only the final rollback
state.
- Keep the Codex plugin and both bundled Skills monotonic at version
0.5.8; no native-Alpha-default behavior is retained by that
metadata-only bump.
## Why / 原因
The current built-in imagegen tool exposes only prompt and
reference-image selection fields, not a transparent-background control.
Direct generation can return real Alpha, but controlled reference-image
generation and editing returned opaque PNGs. Native transparency is
therefore not reliable enough to be the product default.
当前内置 imagegen 仅暴露提示词和参考图选择字段，未暴露透明背景控制。直接生图可以返回真实
Alpha，但受控参考图生图与编辑返回了不透明 PNG，因此原生透明能力尚不具备默认投产条件。
## Validation / 验证
- `./script/validate_pre_push.sh`
- `./script/changelog_fragments.py policy --base-ref
5e94852241 --release-preparation false`
- `uv run --with pillow python -m unittest discover -s
skills/agent-pet-maker/tests -p test_*.py` — 88 passed
- `cargo test -p petcore --test integration_b --locked` — 42 passed
- `DEVELOPER_DIR=/Applications/Xcode.app/Contents/Developer swift test
--package-path apps/macos --filter PortableMakerSkillManagementTests` —
5 passed
- Behavioral tree comparison matches PR #58 parent
`2844e0803734247f16d3667711479856249d13ae`; only monotonic 0.5.8
metadata, its matching Swift expectations, and the corrected retained
changelog fragment differ.
## Development claim / 开发声明
- Domain: `maker-generation`
- Claim: `maker-skills`
- Base commit: `5e9485224140e5f30ced42d598eba87b4f8b26e6`
- Release preparation: `no`
- Scope note: direct hotfix that atomically reverts the cross-contract
PR #58 delivery.
- Focused validation:
- `cargo test -p petcore --test integration_b --locked`
- `./script/validate_pet_skills.sh`
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Co-authored-by: gd-ops <gd-ops@xmfunny.com>
