chore: [env] .env.example 업데이트 및 .gitignore 정리

- .env.example을 SAM 프로젝트 실제 키 구조로 업데이트
- .gitignore에 !.env.example 예외 추가
- GCS_* 중복 키 제거, Gemini/Claude/Vertex 키 섹션 추가

app/Models/Tenants/Card.php

@@ -22,17 +22,8 @@
  * @property string $expiry_date
  * @property string|null $card_password_encrypted
  * @property string $card_name
- * @property string|null $card_type
- * @property string|null $alias
- * @property string|null $cvc_encrypted
- * @property int|null $payment_day
- * @property float|null $total_limit
- * @property float|null $used_amount
- * @property float|null $remaining_limit
  * @property string $status
- * @property bool $is_manual
  * @property int|null $assigned_user_id
- * @property string|null $memo
  * @property int|null $created_by
  * @property int|null $updated_by
  * @property int|null $deleted_by
@@ -46,22 +37,13 @@ class Card extends Model
     protected $fillable = [
         'tenant_id',
         'card_company',
-        'card_type',
         'card_number_encrypted',
         'card_number_last4',
         'expiry_date',
         'card_password_encrypted',
         'card_name',
-        'alias',
-        'cvc_encrypted',
-        'payment_day',
-        'total_limit',
-        'used_amount',
-        'remaining_limit',
         'status',
-        'is_manual',
         'assigned_user_id',
-        'memo',
         'created_by',
         'updated_by',
         'deleted_by',
@@ -70,29 +52,12 @@ class Card extends Model
     protected $hidden = [
         'card_number_encrypted',
         'card_password_encrypted',
-        'cvc_encrypted',
-    ];
-
-    protected $appends = [
-        'csv',
     ];
 
     protected $attributes = [
         'status' => 'active',
-        'is_manual' => false,
     ];
 
-    protected function casts(): array
-    {
-        return [
-            'payment_day' => 'integer',
-            'total_limit' => 'decimal:2',
-            'used_amount' => 'decimal:2',
-            'remaining_limit' => 'decimal:2',
-            'is_manual' => 'boolean',
-        ];
-    }
-
     // =========================================================================
     // 관계 정의
     // =========================================================================
@@ -162,38 +127,6 @@ public function getDecryptedCardPassword(): ?string
             : null;
     }
 
-    /**
-     * CVC/CVV 암호화 설정
-     */
-    public function setCvc(?string $cvc): void
-    {
-        $this->cvc_encrypted = $cvc
-            ? Crypt::encryptString($cvc)
-            : null;
-    }
-
-    /**
-     * CVC/CVV 복호화 조회
-     */
-    public function getDecryptedCvc(): ?string
-    {
-        return $this->cvc_encrypted
-            ? Crypt::decryptString($this->cvc_encrypted)
-            : null;
-    }
-
-    // =========================================================================
-    // Accessor (JSON 직렬화용)
-    // =========================================================================
-
-    /**
-     * CSV(CVC) 복호화 값 — $appends로 JSON 응답에 포함
-     */
-    public function getCsvAttribute(): ?string
-    {
-        return $this->getDecryptedCvc();
-    }
-
     // =========================================================================
     // 헬퍼 메서드
     // =========================================================================