serialization.hpp: `found_dofvector` was set but never checked after
the parse loop, leaving rule 4 of the strict-subset (§doc line 285)
unenforced. Add the missing post-loop throw so a ConformalResult XML
that omits the <DOFVector> element is rejected with a clear error
instead of silently returning an empty x. Update the docstring to
remove the misleading "silently returns" note.
finding-orchestration.md: mark H3/H4/H5/V5/V6 ✅ and record the S3
session as complete. Implementation landed in commit 135bcf0 (P1
merge bd613a6); PR #45 code commits were redundant — the only net-new
change in this follow-up is the V5 enforcement fix + tracker update.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>