feat: add /admin command to list room admins

Implement /admin command as specified in issue #50:
- Lists all admin user IDs for the current room
- Output format: 'Room Admins:\n- @user1\n- @user2'
- Shows 'No admins configured for this room.' if none exist
- Available to everyone (no permission check needed)

Changes:
- Add cmd_admin function to commands.py
- Register CommandHandler('admin', cmd_admin) in bot.py
- Add /admin to command menu in post_init
- Update /help to include /admin command

Closes #50

apps/telegram-bot/commands.py

@@ -321,7 +321,23 @@ async def cmd_help(update: Update, ctx: ContextTypes.DEFAULT_TYPE) -> None:
         "/delete <id> — delete bounty\n"
         "/track <id> — track a bounty (groups only)\n"
         "/untrack <id> — stop tracking (groups only)\n"
+        "/admin — list room admins\n"
         "/start — re-initialize\n"
         "/help — this message",
         disable_web_page_preview=True,
     )
+
+
+async def cmd_admin(update: Update, ctx: ContextTypes.DEFAULT_TYPE) -> None:
+    room_id = get_room_id(update)
+    admin_ids = BOUNTY_SERVICE.list_admins(room_id)
+
+    if not admin_ids:
+        await update.message.reply_text("No admins configured for this room.")
+        return
+
+    lines = [f"Room Admins:"]
+    for admin_id in admin_ids:
+        lines.append(f"- @{admin_id}")
+
+    await update.message.reply_text("\n".join(lines))