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-create/scripts/create_session.sh

@@ -196,7 +196,10 @@ cleanup_tmux_on_error() {
 trap cleanup_tmux_on_error EXIT
 
 # TUI 준비 대기
-wait_for_tui_ready "$SESSION_NAME" "$AGENT"
+if ! wait_for_tui_ready "$SESSION_NAME" "$AGENT"; then
+  echo "ERROR: agent TUI never became ready — aborting (rollback via trap)" >&2
+  exit 1
+fi
 
 # pane 메타 캡처
 PANE_PID=$(_tmux list-panes -t "$SESSION_NAME" -F '#{pane_pid}' 2>/dev/null || echo "")
@@ -381,7 +384,10 @@ On failure run:      $pub --event error     --detail '<one-line reason>'.
 Task: $SUBMIT_JOB_PROMPT"
 
   # Inject instructions into the tmux pane
-  inject_instructions "$SESSION_NAME" "$instructions" "$DELEGATE_JOB_ID"
+  if ! inject_instructions "$SESSION_NAME" "$instructions" "$DELEGATE_JOB_ID"; then
+    delegate_publish_event "$DELEGATE_JOB_ID" error "instruction injection failed (prompt-lock, rc=$?)"
+    exit 1
+  fi
   
   delegate_publish_event "$DELEGATE_JOB_ID" started "multi-agent-mux session created and instructions injected"
   WD_PID=$(start_watchdog "$DELEGATE_JOB_ID" "$WORKSPACE")