refactor(skills): cleanup dead code + full workflow A→B→C→D integration

Cleanup:
- Remove unused validate_yaml() helper from lib.sh
- Remove USER_MANUAL.html + mqtt-broker-setup.html (no refs found)

Workflow A (create_session ↔ delegate-job):
- Add --submit-job <prompt> option to create_session.sh
- Auto-register session in delegate-job registry, store delegate_job_id in YAML

Workflow B (push-based monitor):
- Migrate reconcile.sh to MQTT subscriber mode (polling fallback preserved)

Workflow C (unified status):
- status.sh now shows session + delegate-job state in single column

Workflow D (audit log + perms):
- JSON job files chmod 600
- create/delete/resume now publish lifecycle events to delegate-job

skills/multi-agent-resume/scripts/update_yaml_resumed.sh

@@ -55,6 +55,19 @@ if [ "$AGENT" = "agy" ] && [ -n "$PANE_PID" ]; then
   CHILD_PID="${CHILD_PID:-0}"
 fi
 
+DELEGATE_JOB_ID=$(env_python "$AGENT_SESSIONS_YAML" SESSION_NAME="$SESSION_NAME" <<'PYEOF'
+import os, yaml
+name = os.environ['SESSION_NAME']
+with open(os.environ['YAML_PATH']) as f:
+    d = yaml.safe_load(f) or {}
+for s in d.get('tmux_sessions', []):
+    if s.get('name') == name:
+        print(s.get('delegate_job_id', '') or '')
+        raise SystemExit(0)
+raise SystemExit(0)
+PYEOF
+)
+
 atomic_dump_yaml "$AGENT_SESSIONS_YAML" \
   SESSION_NAME="$SESSION_NAME" UUID="$UUID" AGENT="$AGENT" NOW_ISO="$NOW_ISO" \
   PANE_PID="$PANE_PID" CHILD_PID="$CHILD_PID" <<'PYEOF'
@@ -104,3 +117,17 @@ snap.pop('terminated_at_epoch', None)
 
 print(f"updated: {name} status=running (resume id -> per-row own id)", flush=True)
 PYEOF
+
+if [ -n "$DELEGATE_JOB_ID" ]; then
+  py_bin="python3"
+  d_dir="$(dirname "${BASH_SOURCE[0]}")"
+  while [ "$d_dir" != "/" ] && [ -n "$d_dir" ]; do
+    if [ -x "$d_dir/.venv/bin/python" ]; then
+      py_bin="$d_dir/.venv/bin/python"
+      break
+    fi
+    d_dir="$(dirname "$d_dir")"
+  done
+  pub_script="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)/delegate-job/scripts/publish_event.py"
+  "$py_bin" "$pub_script" --job "$DELEGATE_JOB_ID" --event progress --detail "resumed" || true
+fi