assertBundleDataComplete's claimed-tar checks pass trivially when discovery
claims nothing (0 claims -> 0 checks) — the exact blind spot that shipped a
4.17 GB app as a 2308-byte config-only bundle. A needs_hdd manifest with
neither HDD data nor volume data now fails the job with an honest Hungarian
error. Red-proof recorded: removing the assertion returns scenario D to
silent hollow success.
executeExport no longer either/or gates user data on needs_hdd — a needs_hdd
app bundles BOTH its HDD mounts and its named volumes (sonarr_config = the
whole app DB was silently dropped pre-fix). exportHDDData returns error and
fails LOUDLY on a basename collision between mounts (the manifest keys tars by
basename; the old code silently overwrote the first tar). EstimateExport made
additive to match, so the fits-on-dest gate counts both. Round-trip placement
test proves a userdata tar restores to <HDD_PATH>/userdata through the
untouched import mapping. Red-proofs recorded: either/or revert fails
scenario A; collision-check removal fails the collision test.