fix: [sales] 무료 체험 기간을 1주일(7일)로 변경

- 가격 시뮬레이터: 1/2/3/6개월 선택 → 없음/1주일 토글로 변경
- promoFreeMonths → promoFreeTrial (boolean)으로 변환
- 연 구독료 계산: 1주일분(7/30) 차감 방식 적용
- 데모 테넌트: free_months → free_trial 필드 변경
- 계약 컨트롤러: validation 규칙 업데이트

app/Http/Controllers/Sales/DemoTenantController.php

@@ -150,7 +150,7 @@ public function store(Request $request)
             'promo_dev_amount' => 'nullable|integer|min:0|max:5000000',
             'promo_dev_waive' => 'nullable|in:0,1',
             'promo_sub_percent' => 'nullable|integer|min:0|max:50',
-            'promo_free_months' => 'nullable|integer|in:0,1,2,3,6',
+            'promo_free_trial' => 'nullable|in:0,1',
             'promo_note' => 'nullable|string|max:200',
         ]);
 
@@ -173,7 +173,7 @@ public function store(Request $request)
                 'dev_discount_amount' => (int) $request->input('promo_dev_amount', 0),
                 'dev_waive' => $request->input('promo_dev_waive') === '1',
                 'sub_discount_percent' => (int) $request->input('promo_sub_percent', 0),
-                'free_months' => (int) $request->input('promo_free_months', 0),
+                'free_trial' => $request->input('promo_free_trial') === '1',
                 'note' => $request->input('promo_note', ''),
                 'applied_at' => now()->toDateTimeString(),
                 'applied_by_user_id' => auth()->id(),

app/Http/Controllers/Sales/SalesContractController.php

@@ -35,7 +35,7 @@ public function saveProducts(Request $request): JsonResponse
             'promotion.dev_discount_amount' => 'nullable|numeric|min:0',
             'promotion.dev_waive' => 'nullable|boolean',
             'promotion.sub_discount_percent' => 'nullable|numeric|min:0|max:50',
-            'promotion.free_months' => 'nullable|integer|in:0,1,2,3,6',
+            'promotion.free_trial' => 'nullable|boolean',
             'promotion.note' => 'nullable|string|max:200',
         ]);