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

ROADMAP.md

@@ -12,6 +12,8 @@ Deliverables:
 
 - Stronger Gold Standard coverage across facts, positions, decisions, todos,
   questions and technical details.
+- Gold coverage for responsibility attribution: discussion, objection, role
+  proximity and department mention must not become ownership.
 - Improved category prompts.
 - Repeatable evaluation workflow.
 - Documented prompt experiment log.