refactor: rename resolve_herdr_workspace to resolve_herdr_session and use herdr_session database field consistently

.agents/skills/multi-agent-mux-resume/scripts/resume_session.sh

@@ -37,7 +37,7 @@ if [ -z "$UUID" ]; then
   exit 1
 fi
 
-HERDR_SERVER_NAME="$(resolve_herdr_workspace "$SESSION_NAME")"
+HERDR_SERVER_NAME="$(resolve_herdr_session "$SESSION_NAME")"
 export HERDR_SERVER_NAME
 
 # 2. If herdr is alive, print warning or attach.