feat(pkgbuilds): add foundry cli package

[anandpant]

Summary

• add the active foundry-cli-bin package targeting shpitdev/foundry-cli
• add checksum-verified release update automation with strict version-derived asset selection
• reject unsafe archive member types, non-normal paths, and all symlink/hardlink members before packaging
• preserve an upstream templates README and synthesize the sentinel only when absent
• represent the shipped proprietary license with LicenseRef-proprietary and synchronize .SRCINFO
• accept foundry_cli_release_tag in version-bump dispatches for release workflow integration

Proof

• ./scripts/validate-packages.sh
• bash -n scripts/*.sh foundry-cli-bin/PKGBUILD foundry-cli-bin/foundry-cli-bin.install
• adversarial archive tests: absolute and traversal paths, escaping symlink, hardlink, and FIFO member rejection
• adversarial asset tests: missing, version-mismatched, and duplicate linux-amd64 candidates
• updater dry run against the v0.0.30 release metadata/archive fixture
• full makepkg --cleanbuild --clean --noconfirm package build against the v0.0.30 release archive
• byte comparison confirms the packaged templates README preserves the upstream file
• packaged binary smoke: foundry-cli version -> foundry-cli 0.0.30
• tracked-tree scan confirms no case-insensitive legacy organization references