Fix chapter_polish: remove empty devon/lane/cora_final context refs

CLP's chapter_roundtable doesn't extract individual editor finals
(it's roster-driven, not hardcoded to Devon/Lane/Cora).
Removed the three empty context references from the polish step hint.
consensus_critique already summarizes all editorial positions.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

templates/chapter_polish.yml

@@ -27,10 +27,6 @@ steps:
       KEY CHANGES REQUESTED:
       {key_changes}
 
-      Devon (Developmental): {devon_final}
-      Lane (Line Editor): {lane_final}
-      Cora (Continuity): {cora_final}
-
       VERDICT: {chapter_verdict}
 
       ---