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-status/scripts/status.sh

@@ -28,38 +28,17 @@ fi
 # Resolved relative to this script — no hardcoded absolute path (review item 6).
 PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../../../../" && pwd)"
 
-DRIFT_JSON="$DRIFT_JSON" env_python "$AGENT_SESSIONS_YAML" PROJECT_ROOT="$PROJECT_ROOT" <<'PYEOF'
-import os, json, glob
-import yaml
+MAM_STATE_JSON="$(load_state_json)" DRIFT_JSON="$DRIFT_JSON" env_python "$AGENT_SESSIONS_YAML" PROJECT_ROOT="$PROJECT_ROOT" <<'PYEOF'
+import os, sys, json, glob
 
-yaml_path = os.environ['YAML_PATH']
 home = os.environ['HOME_DIR']
 claude_project_dir = os.environ.get('CLAUDE_PROJECT_DIR', f"{home}/.claude/projects")
 drift = json.loads(os.environ['DRIFT_JSON'])
 
-db_path = os.path.splitext(yaml_path)[0] + '.db'
-d = {}
-import sqlite3
 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 {}
+    d = json.loads(os.environ.get('MAM_STATE_JSON', '{}'))
 except Exception:
-    pass
+    d = {}
 
 alive = set(drift.get('tmux_sessions_alive', []))
 drift_by_name = {}