fix(refactor): address reviewer findings R-1..R-8, achieve 31/31 test pass

.agents/skills/multi-agent-mux-resume/SKILL.md

@@ -76,7 +76,7 @@ if [ -z "$UUID" ]; then
   exit 1
 fi
 
-export HERDR_SERVER_NAME="$(resolve_herdr_workspace "$SESSION_NAME")"
+export HERDR_SESSION_NAME="$(resolve_herdr_workspace "$SESSION_NAME" "$WORKSPACE")"
 
 # 2. If herdr is alive, attach. Done.
 if herdr has-session -t "$SESSION_NAME" 2>/dev/null; then