Bootstraps linuxdeploy (1-alpha-20251107-1) and linuxdeploy-plugin-qt
(1-alpha-20250213-1) to scripts/.cache/ on first run. Dual-mode:
sourceable (exports $LINUXDEPLOY_BIN / $LINUXDEPLOY_PLUGIN_QT_BIN) or
executable (prints paths). Pinned dated snapshots per spec §F9 — no
rolling continuous tag.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Emits <upstream-tag>-seth<N> to stdout. Pure logic, no side effects.
5/5 bats tests pass; output verified as 3.99-master618-seth1.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>