1. converter panic (5 unit tests): "FIXME_CHECKSUM".repeat(4) is only
56 chars but was sliced to [..64], causing index-out-of-bounds panic.
Both crux.rs and gentoo.rs converters now use "a".repeat(64) as the
placeholder checksum instead.
2. dpack list/check exit code 1: these commands call PackageDb::open()
which tries to create /var/lib/dpack/db — fails without root.
Test runner now creates a temp dpack.conf pointing at a writable
temp directory with repos symlinked from the project. Also added
search and info smoke tests.
3. host.ovmf: not a code bug — edk2-ovmf just needs to be installed
on the test VM (sudo pacman -S edk2-ovmf --noconfirm).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>