fix: [finance] 계정과목 추가 시 tenant_id 불일치 수정 및 UX 개선

app/Http/Controllers/Finance/JournalEntryController.php

@@ -865,6 +865,13 @@ public function accountCodeStore(Request $request): JsonResponse
             'category' => 'nullable|string|max:50',
         ]);
 
+        // TenantScope와 동일한 순서로 tenant_id 결정
+        $tenantId = $request->attributes->get('tenant_id')
+            ?? $request->header('X-TENANT-ID')
+            ?? session('selected_tenant_id')
+            ?? auth()->user()?->tenant_id
+            ?? 1;
+
         if (AccountCode::where('code', $validated['code'])->exists()) {
             return response()->json([
                 'success' => false,
@@ -875,7 +882,7 @@ public function accountCodeStore(Request $request): JsonResponse
         $maxSort = AccountCode::max('sort_order') ?? 0;
 
         $accountCode = AccountCode::create([
-            'tenant_id' => session('selected_tenant_id', 1),
+            'tenant_id' => (int) $tenantId,
             'code' => $validated['code'],
             'name' => $validated['name'],
             'category' => $validated['category'] ?? null,