fix(skills): evidence-based prompt delivery (send_keys_safe) to end prompt-lock (FW-W2)

- Add send_keys_safe + quiescence/dialog-detection helpers to lib.sh:
  keys are sent on pane evidence, never fixed timers; distinct exit
  codes 1-4; dialogs are never blindly Enter-ed
- inject_instructions delegates to send_keys_safe; create --submit-job
  publishes a terminal error event on delivery failure (no zombie jobs)
- wait_for_tui_ready: drop dialog-ambiguous tokens, treat open dialogs
  as not-ready, return 1 on timeout instead of proceeding
- delegate-job wrapper: replace copy-pasted raw paste/C-m block with
  lib.sh send_keys_safe (restores single source of truth)
- resume: conditional signature-gated dialog handling replaces blind
  Enter/Down/Enter; stop --graceful delivers exitkey safely, fallback
  chain unchanged
- create SKILL: passive capture-pane probe instead of stray Enter
- Mark FW-W2 resolved; add 3-agent analysis/plan reports

.agents/skills/multi-agent-mux-delegate-job/multi-agent-mux-delegate-job

@@ -362,11 +362,11 @@ run_agent() {
   fi
 
   echo "살아있는 에이전트 세션 '$sess'에 작업을 위임합니다..."
-  $_tmux set-buffer -b "job_buf_$job_id" "$instructions"
-  $_tmux paste-buffer -b "job_buf_$job_id" -t "$sess"
-  sleep 0.5
-  $_tmux send-keys -t "$sess" C-m
-  $_tmux delete-buffer -b "job_buf_$job_id"
+  source "$SCRIPT_DIR/../lib.sh"
+  if ! send_keys_safe "$sess" "$instructions" "$job_id"; then
+    echo "ERROR: 프롬프트 주입 실패 — 세션 '$sess' (프롬프트 잠금 의심)" >&2
+    return 1
+  fi
   
   echo "작업이 세션 '$sess'에 전송되었습니다. (연결하려면: $_tmux attach -t $sess)"
   trap - EXIT