Seven cases run each generated `sh.tangled.*` struct over every captured record, asserting both what parses and reserializes unchanged and what a lexicon-faithful type refuses. The read paths' permissiveness rested on four doc comments and no test, so a regeneration against a tightened schema would have surfaced as a record that silently stopped listing. It now fails here, naming the collection. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Change-Id: Idff9047b3002522cd8c0fbbf210ab9e0f796ba43