chore(stop,resume): drop what Issue #63 left unused (Issue #63)

- workspace_uuid.py: the unused sys import.
- stop_session.sh: the orphan CAPTURE_ID and the blank padding that kept
  later line numbers; the inventory pins follow the move instead.
- lib.sh: capture_conversation_id, which nothing calls any more.
- resume SKILL.md: the flow names the session-id decision (session_ids.py),
  not resolve_session_id.sh.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.agents/skills/multi-agent-mux-stop/scripts/stop_session.sh

@@ -67,7 +67,6 @@ HERDR_SERVER_OPT=""
 HERDR_WORKSPACE_OPT=""
 PURGE=0
 YES=0
-CAPTURE_ID=1
 GRACEFUL=1
 REASON="manual_stop"
 STOP_MODE=1
@@ -224,10 +223,6 @@ if [ -n "$TARGET_CWD" ]; then
   else echo "WARN: no conversation id recorded before stop${STOP_ID_NOTE:+ - $STOP_ID_NOTE}"; fi
 fi
 
-
-
-# (end of pre-kill id decision)
-
 delegate_publish_event "$DELEGATE_JOB_ID" progress "terminating" "$DELEGATE_JOB_TOKEN" "$DELEGATE_JOB_ATTEMPT"
 
 # graceful 종료: send-keys 로 정상 종료 유도 → 폴백 체인 (SIGTERM → SIGKILL).