feat: [finance] 계정과목 확장 및 전표 연동 시스템 구현

- AccountCode 모델/서비스 확장 (업데이트, 기본 계정과목 시딩)
- JournalSyncService 추가 (전표 자동 연동)
- SyncsExpenseAccounts 트레이트 추가
- CardTransactionController, TaxInvoiceController 기능 확장
- expense_accounts 테이블에 전표 연결 컬럼 마이그레이션
- account_codes 테이블 확장 마이그레이션
- 전체 테넌트 기본 계정과목 시딩 마이그레이션

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

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

@@ -4,7 +4,9 @@
 
 use App\Helpers\ApiResponse;
 use App\Http\Controllers\Controller;
+use App\Models\Tenants\JournalEntry;
 use App\Services\CardTransactionService;
+use App\Services\JournalSyncService;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Request;
 
@@ -14,7 +16,8 @@
 class CardTransactionController extends Controller
 {
     public function __construct(
-        protected CardTransactionService $service
+        protected CardTransactionService $service,
+        protected JournalSyncService $journalSyncService,
     ) {}
 
     /**
@@ -148,4 +151,105 @@ public function destroy(int $id): JsonResponse
             return $this->service->destroy($id);
         }, __('message.deleted'));
     }
+
+    // =========================================================================
+    // 분개 (Journal Entries)
+    // =========================================================================
+
+    /**
+     * 카드 거래 분개 조회
+     */
+    public function getJournalEntries(int $id): JsonResponse
+    {
+        return ApiResponse::handle(function () use ($id) {
+            $sourceKey = "card_{$id}";
+            $data = $this->journalSyncService->getForSource(
+                JournalEntry::SOURCE_CARD_TRANSACTION,
+                $sourceKey
+            );
+
+            if (! $data) {
+                return ['items' => []];
+            }
+
+            // 프론트엔드가 기대하는 items 형식으로 변환
+            $items = array_map(fn ($row) => [
+                'id' => $row['id'],
+                'supply_amount' => $row['debit_amount'],
+                'tax_amount' => 0,
+                'account_code' => $row['account_code'],
+                'deduction_type' => 'deductible',
+                'vendor_name' => $row['vendor_name'],
+                'description' => $row['memo'],
+                'memo' => '',
+            ], $data['rows']);
+
+            return ['items' => $items];
+        }, __('message.fetched'));
+    }
+
+    /**
+     * 카드 거래 분개 저장
+     */
+    public function storeJournalEntries(Request $request, int $id): JsonResponse
+    {
+        return ApiResponse::handle(function () use ($request, $id) {
+            $validated = $request->validate([
+                'items' => 'required|array|min:1',
+                'items.*.supply_amount' => 'required|integer|min:0',
+                'items.*.tax_amount' => 'required|integer|min:0',
+                'items.*.account_code' => 'required|string|max:20',
+                'items.*.deduction_type' => 'nullable|string|max:20',
+                'items.*.vendor_name' => 'nullable|string|max:200',
+                'items.*.description' => 'nullable|string|max:500',
+                'items.*.memo' => 'nullable|string|max:500',
+            ]);
+
+            // 카드 거래 정보 조회 (날짜용)
+            $transaction = $this->service->show($id);
+            if (! $transaction) {
+                throw new \Illuminate\Database\Eloquent\ModelNotFoundException;
+            }
+
+            $entryDate = $transaction->used_at
+                ? $transaction->used_at->format('Y-m-d')
+                : ($transaction->withdrawal_date?->format('Y-m-d') ?? now()->format('Y-m-d'));
+
+            // items → journal rows 변환 (각 item을 차변 행으로)
+            $rows = [];
+            foreach ($validated['items'] as $item) {
+                $amount = ($item['supply_amount'] ?? 0) + ($item['tax_amount'] ?? 0);
+                $rows[] = [
+                    'side' => 'debit',
+                    'account_code' => $item['account_code'],
+                    'debit_amount' => $amount,
+                    'credit_amount' => 0,
+                    'vendor_name' => $item['vendor_name'] ?? '',
+                    'memo' => $item['description'] ?? $item['memo'] ?? '',
+                ];
+            }
+
+            // 대변 합계 행 (카드미지급금)
+            $totalAmount = array_sum(array_column($rows, 'debit_amount'));
+            $rows[] = [
+                'side' => 'credit',
+                'account_code' => '25300', // 미지급금 (표준 코드)
+                'account_name' => '미지급금',
+                'debit_amount' => 0,
+                'credit_amount' => $totalAmount,
+                'vendor_name' => $transaction->merchant_name ?? '',
+                'memo' => '카드결제',
+            ];
+
+            $sourceKey = "card_{$id}";
+
+            return $this->journalSyncService->saveForSource(
+                JournalEntry::SOURCE_CARD_TRANSACTION,
+                $sourceKey,
+                $entryDate,
+                "카드거래 분개 (#{$id})",
+                $rows,
+            );
+        }, __('message.created'));
+    }
 }