feat(skills): implement state loader DRY (OP-5) and Job-centric directory structure

- Extract load_state_json centralized helper inside lib.sh to unify state querying
- Refactor status, resume, stop, and monitor scripts to fetch state via MAM_STATE_JSON env var to avoid stdin pipeline collisions
- Restructure delegate-job to provision .mam/jobs/<job_id>/brief.md and direct agents to it, minimizing token size and preventing TUI paste freezes
- Harden send_keys_safe submission loop with was_popup state capture and edge case guards, preventing timing spin false-positives
- Passed cross-verification approved PASS from Planner Claude session

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

@@ -107,6 +107,25 @@ cmd_submit() {
       --max-iterations "$MAX_ITERATIONS")"
   echo "registered job: $JOB_ID"
 
+  # 1-1) Provision job directory and write direct brief.md (MAM Job Restructuring)
+  local job_dir="$REGISTRY_DIR/$JOB_ID"
+  if [[ "$DRY_RUN" != "1" ]]; then
+    mkdir -p "$job_dir"
+    cat <<EOF > "$job_dir/brief.md"
+# 📋 Brief: Job $JOB_ID Delegation
+
+- **Job ID**: $JOB_ID
+- **Target Agent**: $AGENT (session: $AGENT_SESSION)
+- **Role**: Worker
+- **Timeout**: $TIMEOUT s (Idle: $IDLE_TIMEOUT s)
+- **Output Report Path**: .mam/jobs/$JOB_ID/$AGENT-reports/report-final.md
+
+## 🔎 Task Description
+$PROMPT
+EOF
+    echo "provisioned job directory: $job_dir"
+  fi
+
   if [[ "$TYPE" == "direct" ]]; then
     # 2) START THE SUBSCRIBER FIRST (ordering dependency — MQTT does not queue
     #    non-retained messages for absent subscribers).
@@ -140,17 +159,7 @@ cmd_submit() {
     # an id from an earlier session is the #1 reason a delegated job sits idle and
     # times out (see SKILL.md "Wrong job_id propagated to the agent"). We make the
     # freshness explicit in the instruction header.
-    local instructions="Your job_id is \"$JOB_ID\" (the one just registered for THIS delegation — read it from the registry record, do NOT reuse any job_id you saw in earlier runs).
-
-On start run:        $pub --event started.
-On permission/tool prompt run: $pub --event permission_required --detail '<tool>:<what>'.
-On progress (optional): $pub --event progress --detail '<short status>'.
-On success run:      $pub --event completed --detail '<one-line summary>'.
-On failure run:      $pub --event error     --detail '<one-line reason>'.
-
-The subscriber for this job_id is already running; your completed/error event ends the job. Exit codes: 0 completed, 1 error, 2 publish failure.
-
-Task: $PROMPT"
+    local instructions="Your job_id is \"$JOB_ID\". Detailed task requirements, instructions, and target output paths are documented in the task brief file at: .mam/jobs/$JOB_ID/brief.md. Please READ and follow .mam/jobs/$JOB_ID/brief.md to complete your work. Commands: start='$pub --event started', success='$pub --event completed --detail <summary>', error='$pub --event error --detail <reason>'."
 
     run_agent "$JOB_ID" "$instructions"
 
@@ -203,6 +212,25 @@ Task: $PROMPT"
       echo "Session: $current_session"
       echo "=================================================="
 
+      # 1-1) Provision job directory and write iteration brief.md (MAM Job Restructuring)
+      local job_dir="$REGISTRY_DIR/$JOB_ID"
+      if [[ "$DRY_RUN" != "1" ]]; then
+        mkdir -p "$job_dir"
+        cat <<EOF > "$job_dir/brief.md"
+# 📋 Brief: Job $JOB_ID Delegation (Iteration $iteration)
+
+- **Job ID**: $JOB_ID
+- **Target Agent/Session**: $current_session
+- **Role**: $current_role
+- **Iteration**: $iteration
+- **Output Report Path**: .mam/jobs/$JOB_ID/${current_session}-reports/report-final.md
+
+## 🔎 Task Description
+$current_prompt
+EOF
+        echo "provisioned iteration brief: $job_dir/brief.md"
+      fi
+
       # Update job details in registry
       "$PY" "$SCRIPT_DIR/scripts/registry.py" --registry-dir "$REGISTRY_DIR" update \
           --job "$JOB_ID" \
@@ -238,17 +266,7 @@ Task: $PROMPT"
 
       # Format instruction block
       local pub="$PY $SCRIPT_DIR/scripts/publish_event.py --registry-dir $REGISTRY_DIR --job $JOB_ID"
-      local instructions="Your job_id is \"$JOB_ID\" (the one just registered for THIS delegation — read it from the registry record, do NOT reuse any job_id you saw in earlier runs).
-
-On start run:        $pub --event started.
-On permission/tool prompt run: $pub --event permission_required --detail '<tool>:<what>'.
-On progress (optional): $pub --event progress --detail '<short status>'.
-On success run:      $pub --event completed --detail '<one-line summary>'.
-On failure run:      $pub --event error     --detail '<one-line reason>'.
-
-The subscriber for this job_id is already running; your completed/error event ends the job. Exit codes: 0 completed, 1 error, 2 publish failure.
-
-Task: $current_prompt"
+      local instructions="Your job_id is \"$JOB_ID\". Detailed task requirements, instructions, and target output paths for iteration $iteration are documented in the task brief file at: .mam/jobs/$JOB_ID/brief.md. Please READ and follow .mam/jobs/$JOB_ID/brief.md to complete your work. Commands: start='$pub --event started', success='$pub --event completed --detail <summary>', error='$pub --event error --detail <reason>'."
 
       # Trigger agent
       run_agent "$JOB_ID" "$instructions" "$current_session"
@@ -389,8 +407,8 @@ run_agent() {
 
   # Before launching the agent, set up error trap to publish error event
   if [ -n "${job_id:-}" ] && [ -n "${PY:-}" ]; then
-    local pub_script="$SCRIPT_DIR/scripts/publish_event.py"
-    trap 'rc=$?; if [ $rc -ne 0 ]; then "$PY" "$pub_script" --job "$job_id" --event error --detail "agent bootstrap failed (exit $rc)"; fi' EXIT
+    pub_script="$SCRIPT_DIR/scripts/publish_event.py"
+    trap "rc=\$?; if [ \$rc -ne 0 ]; then \"$PY\" \"$pub_script\" --job '$job_id' --event error --detail 'agent bootstrap failed (exit '\$rc')'; fi" EXIT
   fi
 
   echo "살아있는 에이전트 세션 '$sess'에 작업을 위임합니다..."