feat(tmux): implement 2-hour inactivity session TTL reaper and prune command

bin/muse-tmux.py

@@ -105,6 +105,40 @@ def cmd_kill(args):
         print(f"Error: {err.strip() or out.strip()}", file=sys.stderr)
         return rc
 
+def cmd_prune(args):
+    ttl_seconds = getattr(args, "ttl", 7200) or 7200
+    rc, out, err = _run_tmux("list-sessions", "-F", "#{session_name} #{session_activity} #{session_attached}")
+    if rc != 0:
+        if "no server running" in (err or "").lower() or rc == 1:
+            print(f"No active tmux server on {SOCKET_PATH}.")
+            return 0
+        print(f"Error listing sessions: {err.strip() or out.strip()}", file=sys.stderr)
+        return rc
+        
+    now = int(time.time())
+    reaped = []
+    kept = []
+    
+    for line in out.strip().splitlines():
+        parts = line.split()
+        if len(parts) >= 3:
+            s_name, s_activity, s_attached = parts[0], int(parts[1]), int(parts[2])
+            idle_time = now - s_activity
+            # Only prune if unattached and idle > TTL
+            if s_attached == 0 and idle_time > ttl_seconds:
+                _run_tmux("kill-session", "-t", s_name)
+                reaped.append((s_name, idle_time))
+            else:
+                kept.append((s_name, idle_time, s_attached))
+                
+    if reaped:
+        print(f"✔ Reaped {len(reaped)} stale unattached session(s) (idle > {ttl_seconds//3600}h):")
+        for s_name, idle in reaped:
+            print(f"  • {s_name} (idle: {idle//60}m)")
+    else:
+        print(f"No stale unattached sessions to reap (all active within {ttl_seconds//3600}h).")
+    return 0
+
 def cmd_attach(args):
     session = args.session
     cmd = [TMUX_BIN, "-S", SOCKET_PATH, "attach", "-t", session]
@@ -144,6 +178,11 @@ def main():
     p_kill.add_argument("session", help="Session name")
     p_kill.set_defaults(func=cmd_kill)
     
+    # prune
+    p_prune = subparsers.add_parser("prune", help="Reap stale unattached sessions inactive for >TTL (default: 7200s / 2h)")
+    p_prune.add_argument("--ttl", type=int, default=7200, help="Inactivity threshold in seconds (default: 7200)")
+    p_prune.set_defaults(func=cmd_prune)
+    
     # attach
     p_att = subparsers.add_parser("attach", help="Attach to a session interactively")
     p_att.add_argument("session", help="Session name")