test: prove Secret Provider rotation preserves pending graph state (SEC-05/08) #267

P0/P1 conformance #216 maps SEC-01–12 case by case. Existing examples already prove concurrent same-type/same-ID ledger isolation and Vault request isolation. The rotation example needs explicit before/after assertions for an existing pending mutation ledger and unrelated Context/business-clock state. This is an evidence gap, not a confirmed runtime defect. Add narrow assertions and required example success markers, execute native examples twice before internal consumption, and reuse unchanged production artifacts where exact source equivalence is proven. No main merge, public release/tag, generator deployment or Actions enablement.