CultElementIds.Holds is the one fact a store marks its header by; a test now
drives it directly over a dictionary value, a list of lists, a list under an
unset element and an element, and over unset ids that hold nothing, so a
mutant that skips any of those branches fails.
C# ReadStoreHeader refused a first-slot string without the cultcache.store.
prefix and then ran RequireSingleFileFormat, which refuses every string that
is not v1, v2 or v3 anyway. The prefix check is gone; a non-header string is
refused as a format this runtime does not read.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Engine tests for the plan (duplicates, format, empty derived source, atomicity, two
cultures, interface unions, key sharing); cache tests for the marker on single-file and
directory stores, override values on write and load, minting that is given back, and the
in-memory-only mark.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
[CultElementId(nameof(Member))] declares an id derived from that member's
invariant text, never random, so content-addressed elements keep encoding to the
same bytes. CultMeshCdnChunkRef derives its id from Offset; PackArtifact sets
it, the Rust pack_content writes it, and the committed content vectors are
re-cut once so both runtimes carry it. Engine tests drive Problems and Assign
directly (InternalsVisibleTo the Caching tests).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
