Skipping stage-native-deps on an admitted receipt kept a tree staged without a piece forever:
get-windows (or its win32 x64 binding, which only the native installer inside staging can fetch),
the macOS get-windows helper, or the host HUD helper (no X11 toolchain on Linux). The receipt
identity cannot see the host fix that would complete it.
The receipt now records `degraded` from the staged tree itself (nativeTreeComplete: every piece
this host can produce for the target is present), and build.mjs reuses only a complete one
(nativeInputsComplete). Gaps no host fix closes — win32-arm64 has no get-windows prebuild, a
cross-target pack never builds the helpers — do not count. Judging the tree rather than each
builder's return value covers soft-fail paths that still return a path (the win32 binding).
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