feat: 增强玩家 API，新增 locale 和时间字段，更新钱包 API 以支持可用余额计算，添加错误码与多语言支持

app/Models/WalletTxn.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+/** 彩票钱包流水 {@see wallet_txns} */
+class WalletTxn extends Model
+{
+    protected $fillable = [
+        'txn_no',
+        'player_id',
+        'wallet_id',
+        'biz_type',
+        'biz_no',
+        'direction',
+        'amount',
+        'balance_before',
+        'balance_after',
+        'status',
+        'external_ref_no',
+        'idempotent_key',
+        'remark',
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'direction' => 'integer',
+            'amount' => 'integer',
+            'balance_before' => 'integer',
+            'balance_after' => 'integer',
+        ];
+    }
+
+    public function player(): BelongsTo
+    {
+        return $this->belongsTo(Player::class);
+    }
+
+    public function wallet(): BelongsTo
+    {
+        return $this->belongsTo(PlayerWallet::class, 'wallet_id');
+    }
+}