future-private: add place order request

src/Requests/PlaceOrderRequestContract.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace Msr\LaravelBitunixApi\Requests;
+
+use Psr\Http\Message\ResponseInterface;
+
+interface PlaceOrderRequestContract
+{
+    /**
+     * Place a new order
+     *
+     * @param string $symbol Trading pair (e.g., 'BTCUSDT')
+     * @param string $qty Amount (base coin)
+     * @param string $side Order direction ('BUY' or 'SELL')
+     * @param string $tradeSide Direction ('OPEN' or 'CLOSE')
+     * @param string $orderType Order type ('LIMIT' or 'MARKET')
+     * @param string|null $price Price of the order (required for LIMIT orders)
+     * @param string|null $positionId Position ID (required when tradeSide is 'CLOSE')
+     * @param string|null $effect Order expiration date
+     * @param string|null $clientId Customize order ID
+     * @param bool|null $reduceOnly Whether to just reduce the position
+     * @param string|null $tpPrice Take profit trigger price
+     * @param string|null $tpStopType Take profit trigger type
+     * @param string|null $tpOrderType Take profit trigger place order type
+     * @param string|null $tpOrderPrice Take profit trigger place order price
+     * @param string|null $slPrice Stop loss trigger price
+     * @param string|null $slStopType Stop loss trigger type
+     * @param string|null $slOrderType Stop loss trigger place order type
+     * @param string|null $slOrderPrice Stop loss trigger place order price
+     * @return ResponseInterface
+     */
+    public function placeOrder(
+        string $symbol,
+        string $qty,
+        string $side,
+        string $tradeSide,
+        string $orderType,
+        ?string $price = null,
+        ?string $positionId = null,
+        ?string $effect = null,
+        ?string $clientId = null,
+        ?bool $reduceOnly = null,
+        ?string $tpPrice = null,
+        ?string $tpStopType = null,
+        ?string $tpOrderType = null,
+        ?string $tpOrderPrice = null,
+        ?string $slPrice = null,
+        ?string $slStopType = null,
+        ?string $slOrderType = null,
+        ?string $slOrderPrice = null
+    ): ResponseInterface;
+}