feat(procurement): 實作採購退回單模組並修復商品選單報錯

database/migrations/tenant/2026_02_25_125537_create_purchase_returns_table.php

@@ -0,0 +1,49 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('purchase_returns', function (Blueprint $table) {
+            $table->id();
+            $table->string('code')->unique()->comment('退回單號');
+            $table->unsignedBigInteger('vendor_id')->comment('廠商 ID');
+            $table->unsignedBigInteger('warehouse_id')->comment('退貨出庫倉庫 ID');
+            $table->unsignedBigInteger('user_id')->comment('建立者 ID');
+            $table->date('return_date')->comment('退貨日期');
+            
+            $table->string('status', 20)->default('draft')->comment('狀態: draft, completed, cancelled');
+            
+            $table->decimal('total_amount', 12, 2)->default(0)->comment('總金額 (不含稅)');
+            $table->decimal('tax_amount', 12, 2)->default(0)->comment('稅金');
+            $table->decimal('grand_total', 12, 2)->default(0)->comment('總計含稅金額');
+            
+            $table->text('remarks')->nullable()->comment('備註');
+            
+            $table->timestamps();
+            $table->softDeletes();
+            
+            // 由於 Modular Monolith 規範，外部模組的 Foreign Key 不一定建立實體約束以避免牽一髮動全身
+            // $table->foreign('vendor_id')->references('id')->on('vendors')->onDelete('restrict');
+            $table->index('code');
+            $table->index('vendor_id');
+            $table->index('warehouse_id');
+            $table->index('status');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('purchase_returns');
+    }
+};

database/migrations/tenant/2026_02_25_125551_create_purchase_return_items_table.php

@@ -0,0 +1,38 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('purchase_return_items', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('purchase_return_id')->constrained('purchase_returns')->onDelete('cascade');
+            $table->unsignedBigInteger('product_id')->comment('商品 ID');
+            
+            $table->decimal('quantity_returned', 10, 2)->comment('退貨數量');
+            $table->decimal('unit_price', 12, 2)->comment('退貨單價');
+            $table->decimal('total_amount', 12, 2)->comment('小計金額');
+            
+            $table->string('batch_number', 100)->nullable()->comment('指定退回之批號');
+            
+            $table->timestamps();
+            
+            $table->index('product_id');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('purchase_return_items');
+    }
+};