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/Inventory/Models/Product.php

@@ -9,7 +9,7 @@ use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Spatie\Activitylog\Traits\LogsActivity;
 use Spatie\Activitylog\LogOptions;
-use App\Modules\Procurement\Models\Vendor; // Cross-module dependency (Procurement)
+
 
 class Product extends Model
 {
@@ -32,7 +32,7 @@ class Product extends Model
     ];
 
     /**
-     * Get the category that owns the product.
+     * 取得該商品所屬的分類。
      */
     public function category(): BelongsTo
     {
@@ -54,10 +54,7 @@ class Product extends Model
         return $this->belongsTo(Unit::class, 'purchase_unit_id');
     }
 
-    public function vendors(): \Illuminate\Database\Eloquent\Relations\BelongsToMany
-    {
-        return $this->belongsToMany(Vendor::class)->withPivot('last_price')->withTimestamps();
-    }
+
 
     public function inventories(): \Illuminate\Database\Eloquent\Relations\HasMany
     {
@@ -83,13 +80,13 @@ class Product extends Model
         $attributes = $properties['attributes'] ?? [];
         $snapshot = $properties['snapshot'] ?? [];
         
-        // Handle Category Name Snapshot
+        // 處理分類名稱快照
         if (isset($attributes['category_id'])) {
             $category = Category::find($attributes['category_id']);
             $snapshot['category_name'] = $category ? $category->name : null;
         }
         
-        // Handle Unit Name Snapshots
+        // 處理單位名稱快照
         $unitFields = ['base_unit_id', 'large_unit_id', 'purchase_unit_id'];
         foreach ($unitFields as $field) {
             if (isset($attributes[$field])) {
@@ -99,7 +96,7 @@ class Product extends Model
             }
         }
         
-        // Always snapshot self name for context (so logs always show "Cola")
+        // 始終對自身名稱進行快照以便於上下文顯示（這樣日誌總是顯示 "可樂"）
         $snapshot['name'] = $this->name;
 
         $properties['attributes'] = $attributes;