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/Procurement/Models/PurchaseOrder.php

@@ -0,0 +1,79 @@
+<?php
+
+namespace App\Modules\Procurement\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use App\Modules\Inventory\Models\Warehouse;
+use App\Modules\Core\Models\User;
+
+class PurchaseOrder extends Model
+{
+    /** @use HasFactory<\Database\Factories\PurchaseOrderFactory> */
+    use HasFactory;
+    use \Spatie\Activitylog\Traits\LogsActivity;
+
+    protected $fillable = [
+        'po_number',
+        'vendor_id',
+        'warehouse_id',
+        'user_id',
+        'order_date',
+        'expected_delivery_date',
+        'status',
+        'total_amount',
+        'notes',
+    ];
+
+    protected $casts = [
+        'order_date' => 'date',
+        'expected_delivery_date' => 'date',
+        'total_amount' => 'decimal:2',
+    ];
+
+    public function getActivitylogOptions(): \Spatie\Activitylog\LogOptions
+    {
+        return \Spatie\Activitylog\LogOptions::defaults()
+            ->logAll()
+            ->logOnlyDirty()
+            ->dontSubmitEmptyLogs();
+    }
+
+    public function tapActivity(\Spatie\Activitylog\Contracts\Activity $activity, string $eventName)
+    {
+        $snapshot = $activity->properties['snapshot'] ?? [];
+        
+        $snapshot['po_number'] = $this->po_number;
+        
+        if ($this->vendor) {
+            $snapshot['vendor_name'] = $this->vendor->name;
+        }
+        if ($this->warehouse) {
+            $snapshot['warehouse_name'] = $this->warehouse->name;
+        }
+
+        $activity->properties = $activity->properties->merge([
+            'snapshot' => $snapshot
+        ]);
+    }
+
+    public function vendor(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(Vendor::class);
+    }
+
+    public function warehouse(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(Warehouse::class);
+    }
+
+    public function user(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    public function items(): \Illuminate\Database\Eloquent\Relations\HasMany
+    {
+        return $this->hasMany(PurchaseOrderItem::class);
+    }
+}

app/Modules/Procurement/Models/PurchaseOrderItem.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace App\Modules\Procurement\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use App\Modules\Inventory\Models\Product;
+
+class PurchaseOrderItem extends Model
+{
+    /** @use HasFactory<\Database\Factories\PurchaseOrderItemFactory> */
+    use HasFactory;
+
+    protected $fillable = [
+        'purchase_order_id',
+        'product_id',
+        'quantity',
+        'unit_price',
+        'subtotal',
+        // 驗收欄位
+        'received_quantity',
+        // 批號與效期 (驗收時填寫)
+        'batch_number',
+        'expiry_date',
+    ];
+
+    protected $casts = [
+        'quantity' => 'decimal:2',
+        'unit_price' => 'decimal:4',
+        'subtotal' => 'decimal:2',
+        'received_quantity' => 'decimal:2',
+        'expiry_date' => 'date',
+    ];
+
+    public function purchaseOrder(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(PurchaseOrder::class);
+    }
+
+    public function product(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    {
+        return $this->belongsTo(Product::class);
+    }
+}

app/Modules/Procurement/Models/Vendor.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace App\Modules\Procurement\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Spatie\Activitylog\Traits\LogsActivity;
+use Spatie\Activitylog\LogOptions;
+use App\Modules\Inventory\Models\Product;
+
+class Vendor extends Model
+{
+    /** @use HasFactory<\Database\Factories\VendorFactory> */
+    use HasFactory, LogsActivity;
+
+    protected $fillable = [
+        'code',
+        'name',
+        'contact_person',
+        'email',
+        'phone',
+        'address',
+        'tax_id',
+        'payment_terms',
+    ];
+
+    public function products(): \Illuminate\Database\Eloquent\Relations\BelongsToMany
+    {
+        return $this->belongsToMany(Product::class)->withPivot('last_price')->withTimestamps();
+    }
+
+    public function purchaseOrders(): \Illuminate\Database\Eloquent\Relations\HasMany
+    {
+        return $this->hasMany(PurchaseOrder::class);
+    }
+
+    public function getActivitylogOptions(): LogOptions
+    {
+        return LogOptions::defaults()
+            ->logAll()
+            ->logOnlyDirty()
+            ->dontSubmitEmptyLogs();
+    }
+
+    public function tapActivity(\Spatie\Activitylog\Contracts\Activity $activity, string $eventName)
+    {
+        $properties = $activity->properties;
+        
+        $snapshot = $properties['snapshot'] ?? [];
+        $snapshot['name'] = $this->name;
+        $properties['snapshot'] = $snapshot;
+
+        $activity->properties = $properties;
+    }
+}