Integration arbitration, not a PR commit: v0.3/v0.4/v0.5 synced body
changes into appendix chapters 00/02/04/06/07 while templates/roles/
sources stayed at v0.2, so check_appendix failed 6 chapters; and
09-ops/10-iteration chapters (v0.5) were invisible to the strict
chapter regex because of the ', v0.5 new' title suffix, breaking
the #214 matrix-vs-appendix test. Direction is sources follow the
appendix (appendix is the tenant-visible authoritative version;
never overwrite v0.5 text with v0.2). 09/10 headers normalized to
strict form (suffix only); 09/10 sources split mechanically from
the appendix; EXPECTED_IDS extended to 11 chapters in the checker
and both appendix tests.