Enforce explicit responsibility attribution

- document responsibility attribution as a project-wide invariant
- prevent inferred ownership in protocol rendering
- add negative gold regression for false responsibility assignment
- document future responsibility evidence and attribution model
- record the real-life benchmark finding

CHANGELOG.md

@@ -27,6 +27,7 @@
 - Consolidation prompt and non-LLM tests for payload construction, grouping
   validation and source fact coverage.
 - Semantic Consolidator V0 benchmark report and consolidated extraction JSON.
+- Gold regression scenario for responsibility attribution integrity.
 
 ### Changed
 
@@ -42,6 +43,9 @@
 - Documented that rendered protocol language should normally match the source
   transcript or consolidated meeting knowledge unless explicitly requested
   otherwise.
+- Added the Responsibility Attribution Invariant across extraction,
+  canonicalization, consolidation, Canonical Meeting Knowledge and output
+  views.
 - Updated decision extraction semantics to include explicit process decisions
   and deferrals.
 - Simplified extraction prompt assembly around prompt files.