feat: 修正庫存與撥補單邏輯並整合文件

1. 修復倉庫統計數據加總與樣式。
2. 修正可用庫存計算邏輯（排除不可銷售倉庫）。
3. 撥補單商品列表加入批號與效期顯示。
4. 修正撥補單儲存邏輯以支援精確批號轉移。
5. 整合 FEATURES.md 至 README.md。

app/Modules/Production/Models/ProductionOrder.php

@@ -4,14 +4,12 @@ namespace App\Modules\Production\Models;
 
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
-use App\Modules\Inventory\Models\Product;
-use App\Modules\Inventory\Models\Warehouse;
-use App\Modules\Core\Models\User;
+use Spatie\Activitylog\Traits\LogsActivity;
+use Spatie\Activitylog\LogOptions;
 
 class ProductionOrder extends Model
 {
-    /** @use HasFactory<\Database\Factories\ProductionOrderFactory> */
-    use HasFactory;
+    use HasFactory, LogsActivity;
 
     protected $fillable = [
         'code',
@@ -27,6 +25,38 @@ class ProductionOrder extends Model
         'remark',
     ];
 
+    protected $casts = [
+        'production_date' => 'date',
+        'expiry_date' => 'date',
+        'output_quantity' => 'decimal:2',
+    ];
+
+    public function getActivitylogOptions(): LogOptions
+    {
+        return LogOptions::defaults()
+            ->logOnly([
+                'code',
+                'status',
+                'output_quantity',
+                'output_batch_number',
+                'production_date',
+                'remark'
+            ])
+            ->logOnlyDirty()
+            ->dontSubmitEmptyLogs()
+            ->setDescriptionForEvent(fn(string $eventName) => "生產工單已{$this->getEventDescription($eventName)}");
+    }
+
+    protected function getEventDescription($eventName): string
+    {
+        return match ($eventName) {
+            'created' => '建立',
+            'updated' => '更新',
+            'deleted' => '刪除',
+            default => $eventName,
+        };
+    }
+
     public static function generateCode()
     {
         $prefix = 'PO' . now()->format('Ymd');
@@ -40,27 +70,28 @@ class ProductionOrder extends Model
         return $prefix . $sequence;
     }
 
-    protected $casts = [
-        'order_date' => 'date',
-        'start_date' => 'datetime',
-        'completion_date' => 'datetime',
-        'quantity' => 'decimal:2',
-        'produced_quantity' => 'decimal:2',
-    ];
-
-    public function product(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    /**
+     * @deprecated 使用 InventoryServiceInterface 獲取產品資訊
+     */
+    public function product()
     {
-        return $this->belongsTo(Product::class);
+        return null;
     }
 
-    public function warehouse(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    /**
+     * @deprecated 使用 InventoryServiceInterface 獲取倉庫資訊
+     */
+    public function warehouse()
     {
-        return $this->belongsTo(Warehouse::class);
+        return null;
     }
 
-    public function user(): \Illuminate\Database\Eloquent\Relations\BelongsTo
+    /**
+     * @deprecated 使用 CoreServiceInterface 獲取使用者資訊
+     */
+    public function user()
     {
-        return $this->belongsTo(User::class);
+        return null;
     }
 
     public function items(): \Illuminate\Database\Eloquent\Relations\HasMany