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-resume/scripts/update_yaml_resumed.sh

@@ -57,40 +57,15 @@ if { [ "$AGENT" = "agy" ] || [ "$AGENT" = "hermes" ] || [ "$AGENT" = "cline" ];
   CHILD_PID="${CHILD_PID:-0}"
 fi
 
-DELEGATE_JOB_ID=$(env_python "$AGENT_SESSIONS_YAML" SESSION_NAME="$SESSION_NAME" <<'PYEOF'
-import os, sys, sqlite3, json, yaml
+DELEGATE_JOB_ID=$(MAM_STATE_JSON="$(load_state_json)" SESSION_NAME="$SESSION_NAME" python3 -c "
+import sys, os, json
 name = os.environ['SESSION_NAME']
-yaml_path = os.environ['YAML_PATH']
-db_path = os.path.splitext(yaml_path)[0] + '.db'
-d = {}
-try:
-    if os.path.exists(db_path):
-        conn = sqlite3.connect(db_path, timeout=60.0)
-        try:
-            row = conn.execute('SELECT data FROM sessions WHERE name=?', (name,)).fetchone()
-            if row:
-                s = json.loads(row[0])
-                print(s.get('delegate_job_id', '') or '')
-                raise SystemExit(0)
-        except sqlite3.OperationalError:
-            pass
-        row = conn.execute('SELECT data FROM state WHERE id=1').fetchone()
-        if row:
-            d = json.loads(row[0])
-        conn.close()
-    elif os.path.exists(yaml_path):
-        with open(yaml_path) as f:
-            d = yaml.safe_load(f) or {}
-except Exception:
-    pass
-
+d = json.loads(os.environ.get('MAM_STATE_JSON', '{}'))
 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
-)
+        sys.exit(0)
+")
 
 atomic_dump_yaml "$AGENT_SESSIONS_YAML" \
   SESSION_NAME="$SESSION_NAME" UUID="$UUID" AGENT="$AGENT" NOW_ISO="$NOW_ISO" \