ci: reuse mcpp smoke sandbox and audit compat licenses

[Sunrisepeak]

Summary

• reuse a single job-local MCPP_HOME across the Linux compat smoke scripts so mcpp sandbox initialization remains one-time per job
• keep each smoke script isolated by default when the shared CI home env var is not provided
• audit every pkgs/c/compat.*.lua license field against the pinned upstream source archive and remove/replace broad MIT entries where the upstream text is more specific or too mixed to represent safely

CI evidence

• PR checks are green on a4f174bb2708b61480c221c3dddd06b183965564: lint, smoke-linux, smoke-macos, smoke-windows
• smoke-linux completed in 9m8s
• Linux job log counts after sharing MCPP_INDEX_SMOKE_MCPP_HOME:
  • Initialize mcpp sandbox layout = 1
  • Bootstrap patchelf into mcpp sandbox = 1
  • Bootstrap ninja into mcpp sandbox = 1
  • Path Validation Error = 0
  • registry cache saved = 1

License audit table

Package	Descriptor license value	Result
compat.bzip2	bzip2-1.0.6	verified unchanged
compat.ftxui	MIT	verified unchanged
compat.glfw	Zlib	verified unchanged
compat.gtest	BSD-3-Clause	verified unchanged
compat.imgui	MIT	verified unchanged
compat.khrplatform	Khronos	changed from generic MIT; upstream header uses Khronos license text
compat.libarchive	BSD-2-Clause, BSD-3-Clause, BSD-2-Clause-NetBSD, CC0-1.0, OpenSSL, Apache-2.0, public-domain	changed from only BSD-2-Clause; compiled libarchive sources include additional license blocks
compat.lua	MIT	verified unchanged
compat.lz4	BSD-2-Clause	verified unchanged for lib/ build surface
compat.mbedtls	Apache-2.0	verified unchanged
compat.opengl	MIT	verified unchanged for installed OpenGL headers
compat.x11	BSD-1-Clause, HPND-sell-variant, ISC, MIT, MIT-Open-Group, X11	changed from generic MIT; upstream COPYING is mixed X.Org historical license text
compat.xau	MIT-Open-Group	changed from generic MIT
compat.xcb	MIT	verified unchanged
compat.xcb-proto	MIT	verified unchanged
compat.xcursor	HPND-sell-variant	changed from generic MIT
compat.xdmcp	MIT-Open-Group	changed from generic MIT
compat.xext	HPND-sell-variant, ISC, MIT, MIT-Open-Group	changed from generic MIT; upstream COPYING is mixed
compat.xfixes	HPND-sell-variant	changed from generic MIT
compat.xi	MIT-Open-Group	changed from generic MIT
compat.xinerama	MIT-Open-Group	changed from generic MIT
compat.xorgproto	empty	changed from generic MIT; protocol bundle has many mixed and partially unclassified COPYING files, so left empty instead of inventing MIT
compat.xrandr	HPND-sell-variant	changed from generic MIT
compat.xrender	HPND-sell-variant	changed from generic MIT
compat.xtrans	HPND-sell-variant, MIT, MIT-Open-Group	changed from generic MIT; upstream COPYING is mixed
compat.xz	0BSD	removed LGPL-2.1-or-later; descriptor builds liblzma sources, which are 0BSD
compat.zlib	Zlib	verified unchanged
compat.zstd	BSD-3-Clause, GPL-2.0-only	added GPLv2 side of the upstream dual license

Verification

• bash -n tests/smoke_compat_core.sh tests/smoke_compat_imgui.sh tests/smoke_compat_archive.sh tests/smoke_compat_imgui_window.sh tests/smoke_compat_portable.sh
• parsed .github/workflows/*.yml with Python/PyYAML
• descriptor baseline grep for required spec, name, xpm, and no leading-v version identifiers
• git diff --check origin/main..HEAD
• GitHub Actions: lint, smoke-linux, smoke-macos, smoke-windows