Scalar K vs array K in two modules: minimal repro panics (unresolved-type
LLVM tripwire), the std-tail topology silently clobbers (0786 family reads
hash.sx's SHA table as its own K). Blocks the PLAN-STDLIB full-tail
follow-up; co-blockers (eager global emission, 0601 comptime-meta,
error-int shifts) noted in the issue.
