feat: 2.4 입금/출금 관리 API 구현

- 마이그레이션: deposits, withdrawals 테이블 생성
- 모델: Deposit, Withdrawal (BelongsToTenant, SoftDeletes)
- 서비스: DepositService, WithdrawalService (CRUD + summary)
- 컨트롤러: DepositController, WithdrawalController
- FormRequest: Store/Update 검증 클래스
- Swagger: 입금/출금 API 문서 (12개 엔드포인트)
- 라우트: /v1/deposits, /v1/withdrawals 등록

app/Models/Tenants/Withdrawal.php

@@ -0,0 +1,92 @@
+<?php
+
+namespace App\Models\Tenants;
+
+use App\Traits\BelongsToTenant;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\SoftDeletes;
+
+class Withdrawal extends Model
+{
+    use BelongsToTenant, SoftDeletes;
+
+    protected $fillable = [
+        'tenant_id',
+        'withdrawal_date',
+        'client_id',
+        'client_name',
+        'bank_account_id',
+        'amount',
+        'payment_method',
+        'account_code',
+        'description',
+        'reference_type',
+        'reference_id',
+        'created_by',
+        'updated_by',
+        'deleted_by',
+    ];
+
+    protected $casts = [
+        'withdrawal_date' => 'date',
+        'amount' => 'decimal:2',
+        'client_id' => 'integer',
+        'bank_account_id' => 'integer',
+        'reference_id' => 'integer',
+    ];
+
+    /**
+     * 결제수단 목록
+     */
+    public const PAYMENT_METHODS = [
+        'cash' => '현금',
+        'transfer' => '계좌이체',
+        'card' => '카드',
+        'check' => '수표',
+    ];
+
+    /**
+     * 거래처 관계
+     */
+    public function client(): BelongsTo
+    {
+        return $this->belongsTo(Client::class);
+    }
+
+    /**
+     * 출금 계좌 관계
+     */
+    public function bankAccount(): BelongsTo
+    {
+        return $this->belongsTo(BankAccount::class);
+    }
+
+    /**
+     * 생성자 관계
+     */
+    public function creator(): BelongsTo
+    {
+        return $this->belongsTo(\App\Models\User::class, 'created_by');
+    }
+
+    /**
+     * 거래처명 조회 (회원/비회원 통합)
+     */
+    public function getDisplayClientNameAttribute(): string
+    {
+        if ($this->client) {
+            return $this->client->name;
+        }
+
+        return $this->client_name ?? '';
+    }
+
+    /**
+     * 결제수단 라벨
+     */
+    public function getPaymentMethodLabelAttribute(): string
+    {
+        return self::PAYMENT_METHODS[$this->payment_method] ?? $this->payment_method;
+    }
+}