feat: 급여 관리 API 및 더미 시더 확장

- 급여 관리 API 추가 (SalaryController, SalaryService, Salary 모델)
  - 급여 목록/상세/등록/수정/삭제
  - 상태 변경 (scheduled/completed)
  - 일괄 상태 변경
  - 통계 조회
- 더미 시더 확장
  - 근태, 휴가, 부서, 사용자 시더 추가
  - 기존 시더 tenant_id/created_by/updated_by 필드 추가
- 부서 서비스 개선 (tree 조회 기능 추가)
- 카드 서비스 수정

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/Models/Members/User.php

@@ -46,6 +46,18 @@ class User extends Authenticatable
         'deleted_at',
     ];
 
+    protected $appends = [
+        'has_account',
+    ];
+
+    /**
+     * 시스템 계정(비밀번호) 보유 여부
+     */
+    public function getHasAccountAttribute(): bool
+    {
+        return ! empty($this->password);
+    }
+
     public function userTenants()
     {
         return $this->hasMany(UserTenant::class);

app/Models/Tenants/Department.php

@@ -9,11 +9,12 @@
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\MorphMany;
+use Illuminate\Database\Eloquent\SoftDeletes;
 use Spatie\Permission\Traits\HasRoles;
 
 class Department extends Model
 {
-    use HasRoles, ModelTrait; // 부서도 권한/역할을 가짐
+    use HasRoles, ModelTrait, SoftDeletes; // 부서도 권한/역할을 가짐
 
     protected $table = 'departments';
 

app/Models/Tenants/Salary.php

@@ -0,0 +1,165 @@
+<?php
+
+namespace App\Models\Tenants;
+
+use App\Models\Members\User;
+use App\Traits\BelongsToTenant;
+use App\Traits\ModelTrait;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\SoftDeletes;
+
+/**
+ * 급여 모델
+ *
+ * @property int $id
+ * @property int $tenant_id
+ * @property int $employee_id
+ * @property int $year
+ * @property int $month
+ * @property float $base_salary
+ * @property float $total_allowance
+ * @property float $total_overtime
+ * @property float $total_bonus
+ * @property float $total_deduction
+ * @property float $net_payment
+ * @property array|null $allowance_details
+ * @property array|null $deduction_details
+ * @property string|null $payment_date
+ * @property string $status
+ * @property int|null $created_by
+ * @property int|null $updated_by
+ * @property int|null $deleted_by
+ */
+class Salary extends Model
+{
+    use BelongsToTenant, ModelTrait, SoftDeletes;
+
+    protected $table = 'salaries';
+
+    protected $fillable = [
+        'tenant_id',
+        'employee_id',
+        'year',
+        'month',
+        'base_salary',
+        'total_allowance',
+        'total_overtime',
+        'total_bonus',
+        'total_deduction',
+        'net_payment',
+        'allowance_details',
+        'deduction_details',
+        'payment_date',
+        'status',
+        'created_by',
+        'updated_by',
+        'deleted_by',
+    ];
+
+    protected $casts = [
+        'base_salary' => 'decimal:2',
+        'total_allowance' => 'decimal:2',
+        'total_overtime' => 'decimal:2',
+        'total_bonus' => 'decimal:2',
+        'total_deduction' => 'decimal:2',
+        'net_payment' => 'decimal:2',
+        'allowance_details' => 'array',
+        'deduction_details' => 'array',
+        'payment_date' => 'date',
+    ];
+
+    protected $attributes = [
+        'status' => 'scheduled',
+        'base_salary' => 0,
+        'total_allowance' => 0,
+        'total_overtime' => 0,
+        'total_bonus' => 0,
+        'total_deduction' => 0,
+        'net_payment' => 0,
+    ];
+
+    // =========================================================================
+    // 관계 정의
+    // =========================================================================
+
+    /**
+     * 직원
+     */
+    public function employee(): BelongsTo
+    {
+        return $this->belongsTo(User::class, 'employee_id');
+    }
+
+    /**
+     * 생성자
+     */
+    public function creator(): BelongsTo
+    {
+        return $this->belongsTo(User::class, 'created_by');
+    }
+
+    /**
+     * 수정자
+     */
+    public function updater(): BelongsTo
+    {
+        return $this->belongsTo(User::class, 'updated_by');
+    }
+
+    // =========================================================================
+    // 헬퍼 메서드
+    // =========================================================================
+
+    /**
+     * 지급 완료 여부
+     */
+    public function isCompleted(): bool
+    {
+        return $this->status === 'completed';
+    }
+
+    /**
+     * 지급 예정 여부
+     */
+    public function isScheduled(): bool
+    {
+        return $this->status === 'scheduled';
+    }
+
+    /**
+     * 상태 변경
+     */
+    public function markAsCompleted(): void
+    {
+        $this->status = 'completed';
+    }
+
+    /**
+     * 상태 변경
+     */
+    public function markAsScheduled(): void
+    {
+        $this->status = 'scheduled';
+    }
+
+    /**
+     * 실지급액 계산
+     */
+    public function calculateNetPayment(): float
+    {
+        return $this->base_salary
+            + $this->total_allowance
+            + $this->total_overtime
+            + $this->total_bonus
+            - $this->total_deduction;
+    }
+
+    /**
+     * 년월 표시
+     */
+    public function getPeriodLabel(): string
+    {
+        return sprintf('%d년 %d월', $this->year, $this->month);
+    }
+}