The seed-drift guard shipped as refuse-boot: the backend exited when
BACKEND_DICT_VERSION disagreed with the flat dir's recorded .seed_version. On
the test contour that turned a harmless-in-intent action — bumping the
TEST_DICT_VERSION variable to the active release (v1.2.1) on a volume seeded as
v1.0.0 — into a crash loop, because DICT_VERSION is the *seed* of a fresh
volume, not the active version (which the admin console drives).
Make the marker authoritative instead: OpenWithVersions resolves the flat dir's
version from .seed_version when present and ignores bootVersion on an
already-seeded volume; bootVersion only seeds a fresh volume's marker. So a
bumped build seed on a live volume is a no-op (it can't relabel live bytes and
can't void games pinned to the prior label), and it correctly seeds the next
fresh volume. The subdirectory scan now skips the resolved seed, so a version
also present as a subdir (e.g. v1.2.1 uploaded via the console while the build
seed is bumped to v1.2.1) is still loaded rather than shadowed by the flat bytes.
Tests: marker-wins over a bumped boot version; a bumped boot keeps the matching
subdir resident (the live-contour case). Docs updated (ARCHITECTURE §5, READMEs,
compose/.env, PRERELEASE DV) from "refuses to boot" to "marker wins / ignored".
Verified locally against v1.2.1: gofmt, build, vet, unit, integration green.
Ilia Denisov