feat: 더미 데이터 시더 추가 및 회계 관련 마이그레이션

- DummyDataSeeder 및 개별 시더 추가 (Client, BadDebt, Deposit 등)
- payments.paid_at nullable 마이그레이션
- subscriptions 취소 컬럼 추가
- clients 테이블 bad_debt 컬럼 제거
- PlanController, ClientService 수정
- 불필요한 claudedocs, flow-test 파일 정리

app/Http/Controllers/Api/V1/PlanController.php

@@ -2,11 +2,11 @@
 
 namespace App\Http\Controllers\Api\V1;
 
+use App\Helpers\ApiResponse;
 use App\Http\Controllers\Controller;
 use App\Http\Requests\V1\Plan\PlanIndexRequest;
 use App\Http\Requests\V1\Plan\PlanStoreRequest;
 use App\Http\Requests\V1\Plan\PlanUpdateRequest;
-use App\Helpers\ApiResponse;
 use App\Services\PlanService;
 use Illuminate\Http\JsonResponse;
 
@@ -21,9 +21,10 @@ public function __construct(
      */
     public function index(PlanIndexRequest $request): JsonResponse
     {
-        $result = $this->planService->index($request->validated());
-
-        return ApiResponse::handle('message.fetched', $result);
+        return ApiResponse::handle(
+            fn () => $this->planService->index($request->validated()),
+            __('message.fetched')
+        );
     }
 
     /**
@@ -31,9 +32,10 @@ public function index(PlanIndexRequest $request): JsonResponse
      */
     public function active(): JsonResponse
     {
-        $result = $this->planService->active();
-
-        return ApiResponse::handle('message.fetched', $result);
+        return ApiResponse::handle(
+            fn () => $this->planService->active(),
+            __('message.fetched')
+        );
     }
 
     /**
@@ -41,9 +43,10 @@ public function active(): JsonResponse
      */
     public function store(PlanStoreRequest $request): JsonResponse
     {
-        $result = $this->planService->store($request->validated());
-
-        return ApiResponse::handle('message.created', $result, 201);
+        return ApiResponse::handle(
+            fn () => $this->planService->store($request->validated()),
+            __('message.created')
+        );
     }
 
     /**
@@ -51,9 +54,10 @@ public function store(PlanStoreRequest $request): JsonResponse
      */
     public function show(int $id): JsonResponse
     {
-        $result = $this->planService->show($id);
-
-        return ApiResponse::handle('message.fetched', $result);
+        return ApiResponse::handle(
+            fn () => $this->planService->show($id),
+            __('message.fetched')
+        );
     }
 
     /**
@@ -61,9 +65,10 @@ public function show(int $id): JsonResponse
      */
     public function update(PlanUpdateRequest $request, int $id): JsonResponse
     {
-        $result = $this->planService->update($id, $request->validated());
-
-        return ApiResponse::handle('message.updated', $result);
+        return ApiResponse::handle(
+            fn () => $this->planService->update($id, $request->validated()),
+            __('message.updated')
+        );
     }
 
     /**
@@ -71,9 +76,10 @@ public function update(PlanUpdateRequest $request, int $id): JsonResponse
      */
     public function destroy(int $id): JsonResponse
     {
-        $this->planService->destroy($id);
-
-        return ApiResponse::handle('message.deleted');
+        return ApiResponse::handle(
+            fn () => $this->planService->destroy($id),
+            __('message.deleted')
+        );
     }
 
     /**
@@ -81,8 +87,9 @@ public function destroy(int $id): JsonResponse
      */
     public function toggle(int $id): JsonResponse
     {
-        $result = $this->planService->toggle($id);
-
-        return ApiResponse::handle('message.updated', $result);
+        return ApiResponse::handle(
+            fn () => $this->planService->toggle($id),
+            __('message.updated')
+        );
     }
 }