fix(skills): support tmux -S flag in capture-pane shim of lib.sh

.agents/reports/canary-projects-multi-agent-mux-reviewer-cline/report-94ce2fcc.md

@@ -37,7 +37,7 @@
 
 ## 계획서 교정사항 반영
 - ~~`HERDR_SESSION_NAME`~~ → **`HERDR_SERVER_NAME`** (스킬 전체가 소비하는 유일한 변수명) ✅
-- ~~`--herdr-session`~~ → **`--herdr-server`** (create_session.sh:63 of 유일한 플래그) ✅
+- ~~`--herdr-session`~~ → **`--herdr-server`** (create_session.sh:63의 유일한 플래그) ✅
 
 ## 제외 항목 (계획서 §1-6)
 - remove.sh / update.sh: tmux/kill 로직 없음 → 수정 불요 ✅

.agents/skills/lib.sh

@@ -363,7 +363,7 @@ except Exception:
     esac
     ;;
   capture-pane)
-    sess=""
+    sess="" src="visible" lines="100"
     while [ $# -gt 0 ]; do
       case "$1" in
         -t)
@@ -374,10 +374,22 @@ except Exception:
           sess="$2"
           shift 2
           ;;
+        -S)
+          # tmux `-S -N` (start N lines above the visible viewport) maps to
+          # herdr `--source recent --lines N`. Non-negative or non-numeric
+          # values keep the default visible viewport read.
+          if [ $# -ge 2 ] && [[ "$2" =~ ^-[0-9]+$ ]]; then
+            src="recent"
+            lines="${2#-}"
+            shift 2
+          else
+            shift
+          fi
+          ;;
         *) shift ;;
       esac
     done
-    _real_herdr agent read "$sess" --source visible --lines 100 2>/dev/null || true
+    _real_herdr agent read "$sess" --source "$src" --lines "$lines" 2>/dev/null || true
     ;;
   send-keys)
     sess="" key=""