chore: 完善模組化架構遷移與修復前端顯示錯誤

- 修正所有模組 Controller 的 Model 引用路徑 (App\Modules\...)
- 更新 ProductionOrder 與 ProductionOrderItem 模型結構以符合新版邏輯
- 修復 resources/js/utils/format.ts 在處理空值時導致 toLocaleString 崩潰的問題
- 清除全域路徑與 Controller 遷移殘留檔案

app/Modules/Finance/Models/UtilityFee.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace App\Modules\Finance\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+class UtilityFee extends Model
+{
+    /** @use HasFactory<\Database\Factories\UtilityFeeFactory> */
+    use HasFactory;
+
+    protected $fillable = [
+        'type', // 'electricity', 'water', 'gas', etc.
+        'billing_period_start',
+        'billing_period_end',
+        'due_date',
+        'amount',
+        'usage_amount', // kWh, m3, etc.
+        'unit', // 度, 立方米
+        'status', // 'pending', 'paid', 'overdue'
+        'paid_at',
+        'payment_method',
+        'notes',
+        'receipt_image_path',
+    ];
+
+    protected $casts = [
+        'billing_period_start' => 'date',
+        'billing_period_end' => 'date',
+        'due_date' => 'date',
+        'paid_at' => 'datetime',
+        'amount' => 'decimal:2',
+        'usage_amount' => 'decimal:2',
+    ];
+}