新增赠送金币功能：任意用户可从自己余额赠送金币给他人，成功后聊天室系统传音广播；职务奖励金币移入管理区，删除管理区私信按钮

app/Http/Controllers/ChatController.php

@@ -1135,4 +1135,73 @@ class ChatController extends Controller
 
         return $isLeveledUp;
     }
+
+    /**
+     * 用户间赠送金币（任何登录用户均可调用）
+     *
+     * 从自己的余额中扣除指定金额，转入对方账户，
+     * 并在房间内通过「系统传音」广播一条赠送提示。
+     */
+    public function giftGold(Request $request): JsonResponse
+    {
+        $request->validate([
+            'to_user' => 'required|string',
+            'room_id' => 'required|integer',
+            'amount' => 'required|integer|min:1|max:999999',
+        ]);
+
+        $sender = Auth::user();
+        $toName = $request->input('to_user');
+        $roomId = $request->integer('room_id');
+        $amount = $request->integer('amount');
+
+        // 不能给自己转账
+        if ($toName === $sender->username) {
+            return response()->json(['status' => 'error', 'message' => '不能给自己赠送哦～']);
+        }
+
+        // 查目标用户
+        $receiver = User::where('username', $toName)->first();
+        if (! $receiver) {
+            return response()->json(['status' => 'error', 'message' => '用户不存在']);
+        }
+
+        // 余额校验
+        if (($sender->jjb ?? 0) < $amount) {
+            return response()->json([
+                'status' => 'error',
+                'message' => '金币不足！您当前余额 '.($sender->jjb ?? 0)." 金币，无法赠送 {$amount} 金币。",
+            ]);
+        }
+
+        // 执行转账（直接操作字段，与 sendFlower 保持一致风格）
+        $sender->decrement('jjb', $amount);
+        $receiver->increment('jjb', $amount);
+
+        // 广播「系统传音」条目至全房间
+        $sysMsg = [
+            'id' => $this->chatState->nextMessageId($roomId),
+            'room_id' => $roomId,
+            'from_user' => '系统传音',
+            'to_user' => '大家',
+            'content' => "💝 【{$sender->username}】 向 【{$toName}】 赠送了 {$amount} 金币！",
+            'is_secret' => false,
+            'font_color' => '#b45309',
+            'action' => '',
+            'sent_at' => now()->toDateTimeString(),
+        ];
+
+        $this->chatState->pushMessage($roomId, $sysMsg);
+        broadcast(new MessageSent($roomId, $sysMsg));
+        SaveMessageJob::dispatch($sysMsg);
+
+        return response()->json([
+            'status' => 'success',
+            'message' => "赠送成功！已向 {$toName} 赠送 {$amount} 金币。",
+            'data' => [
+                'my_jjb' => $sender->fresh()->jjb,
+                'target_jjb' => $receiver->fresh()->jjb,
+            ],
+        ]);
+    }
 }