修正上架時 Google Play 檢查出的 issue

lib/leave/leave_api.dart

@@ -191,7 +191,7 @@ class LeaveApiService {
       return await _apiService.fetchProcedure<Map<String, dynamic>>(
         procedureEndpoint: "bpm_sign_history",
         params: params,
-        fromJson: (json) => json as Map<String, dynamic>,
+        fromJson: (json) => json,
       );
     } catch (e) {
       print("LeaveApiService.fetchSignHistory 異常: $e");

lib/leave/leave_detail.dart

@@ -1,5 +1,4 @@
 import 'package:flutter/material.dart';
-import 'package:intl/intl.dart';
 import './leave_model.dart';
 import './leave_api.dart';
 
@@ -242,7 +241,7 @@ class _LeaveDetailState extends State<LeaveDetail> {
                     _buildTableCell(displayTime),
                   ],
                 );
-              }).toList(),
+              }),
             ],
           ),
         );

lib/leave/leave_form.dart

@@ -130,7 +130,7 @@ class _LeaveFormState extends State<LeaveForm> {
           children: [
             // 假別選擇 (顯示名稱，存入代碼)
             DropdownButtonFormField<LeaveType>(
-              value: _selectedType,
+              initialValue: _selectedType,
               decoration: const InputDecoration(labelText: '請假類別', border: OutlineInputBorder()),
               // 將 API 取得的資料轉換為選單項目
               items: _dbLeaveTypes.map((t) => DropdownMenuItem(