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-monitor/scripts/reconcile.sh

@@ -15,6 +15,7 @@
 set -euo pipefail
 
 source "$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)/lib.sh"
+export WORKSPACE_ROOT
 
 STATE_DIR="${AGENT_SESSIONS_STATE_DIR:-$WORKSPACE_ROOT/.cache/multi-agent-mux-monitor}"
 
@@ -304,31 +305,18 @@ claude_project_dir = os.environ.get('CLAUDE_PROJECT_DIR', f"{home}/.claude/proje
 
 now_iso = datetime.now(timezone.utc).strftime('%Y-%m-%dT%H:%M:%SZ')
 
-# atomic 래퍼에서는 d 가 이미 로드돼 있음. env_python(dry-run)에서는 여기서 로드.
 try:
     d
 except NameError:
-    import sqlite3
-    db_path = os.path.splitext(yaml_path)[0] + '.db'
+    import subprocess
     d = {}
     try:
-        if os.path.exists(db_path):
-            conn = sqlite3.connect(db_path, timeout=60.0)
-            row = conn.execute('SELECT data FROM state WHERE id=1').fetchone()
-            if row: d = json.loads(row[0])
-            
-            try:
-                db_sessions = []
-                cursor = conn.execute('SELECT data FROM sessions')
-                for s_row in cursor.fetchall():
-                    db_sessions.append(json.loads(s_row[0]))
-                d['tmux_sessions'] = db_sessions
-            except sqlite3.OperationalError:
-                pass
-            conn.close()
-        elif os.path.exists(yaml_path):
-            with open(yaml_path) as f:
-                d = yaml.safe_load(f) or {}
+        ws_root = os.environ.get('WORKSPACE_ROOT')
+        if not ws_root:
+            ws_root = os.path.abspath(os.path.join(os.path.dirname(__file__), '../../../..'))
+        script = f"source '{ws_root}/.agents/skills/lib.sh' && load_state_json"
+        out = subprocess.check_output(['bash', '-c', script], stderr=subprocess.DEVNULL)
+        d = json.loads(out.decode('utf-8'))
     except Exception:
         pass