退款治理：手动修正状态增加安全阀并补测试

app/Http/Controllers/Admin/PlatformOrderController.php

@@ -584,7 +584,8 @@ class PlatformOrderController extends Controller
     {
         $admin = $this->ensurePlatformAdmin($request);
 
-        if ((float) ($order->paid_amount ?? 0) <= 0) {
+        $paidAmount = (float) ($order->paid_amount ?? 0);
+        if ($paidAmount <= 0) {
             return redirect()->back()->with('warning', '当前订单已付金额为 0，无法标记为已退款。');
         }
 
@@ -592,6 +593,12 @@ class PlatformOrderController extends Controller
             return redirect()->back()->with('warning', '当前订单已是已退款状态，无需重复操作。');
         }
 
+        // 安全阀：仅允许在“退款总额已达到/超过已付金额”时标记为已退款
+        $refundTotal = (float) $this->refundTotalForOrder($order);
+        if (round($refundTotal * 100) + 1 < round($paidAmount * 100)) {
+            return redirect()->back()->with('warning', '退款总额尚未达到已付金额，无法标记为已退款。请先核对/补齐退款记录。');
+        }
+
         $now = now();
         $order->payment_status = 'refunded';
         $order->refunded_at = $order->refunded_at ?: $now;
@@ -617,7 +624,8 @@ class PlatformOrderController extends Controller
     {
         $admin = $this->ensurePlatformAdmin($request);
 
-        if ((float) ($order->paid_amount ?? 0) <= 0) {
+        $paidAmount = (float) ($order->paid_amount ?? 0);
+        if ($paidAmount <= 0) {
             return redirect()->back()->with('warning', '当前订单已付金额为 0，无法标记为部分退款。');
         }
 
@@ -625,6 +633,15 @@ class PlatformOrderController extends Controller
             return redirect()->back()->with('warning', '当前订单已是部分退款状态，无需重复操作。');
         }
 
+        // 安全阀：部分退款需要“退款总额>0 且未达到已付金额”
+        $refundTotal = (float) $this->refundTotalForOrder($order);
+        if (round($refundTotal * 100) <= 0) {
+            return redirect()->back()->with('warning', '退款总额为 0，无法标记为部分退款。');
+        }
+        if (round($refundTotal * 100) + 1 >= round($paidAmount * 100)) {
+            return redirect()->back()->with('warning', '退款总额已达到/超过已付金额，建议标记为已退款。');
+        }
+
         $now = now();
         $order->payment_status = 'partially_refunded';
         $order->refunded_at = $order->refunded_at ?: $now;
@@ -650,10 +667,15 @@ class PlatformOrderController extends Controller
     {
         $admin = $this->ensurePlatformAdmin($request);
 
-        if ((float) ($order->paid_amount ?? 0) <= 0) {
+        $paidAmount = (float) ($order->paid_amount ?? 0);
+        if ($paidAmount <= 0) {
             return redirect()->back()->with('warning', '当前订单已付金额为 0，无法标记为已支付。');
         }
 
+        if ((string) $order->payment_status === 'unpaid') {
+            return redirect()->back()->with('warning', '当前订单为未支付状态，不允许直接标记为已支付，请使用「标记支付并生效」或补回执/金额后再处理。');
+        }
+
         if ((string) $order->payment_status === 'paid') {
             return redirect()->back()->with('warning', '当前订单已是已支付状态，无需重复操作。');
         }
@@ -1451,6 +1473,25 @@ class PlatformOrderController extends Controller
 
         return $sum;
     }
+
+    private function refundTotalForOrder(PlatformOrder $order): float
+    {
+        // 优先读扁平字段 refund_summary.total_amount
+        $total = data_get($order->meta, 'refund_summary.total_amount');
+        if ($total !== null) {
+            return (float) $total;
+        }
+
+        // 回退：遍历 refund_receipts[].amount
+        $refunds = (array) (data_get($order->meta, 'refund_receipts', []) ?? []);
+        $sum = 0.0;
+        foreach ($refunds as $r) {
+            $sum += (float) (data_get($r, 'amount') ?? 0);
+        }
+
+        return $sum;
+    }
+
     protected function sumReceiptAmount($orders): float
     {
         $total = 0.0;