feat(Admin/Company): 擴充業務類型與合約期間功能，補齊多語系翻譯詞條

database/migrations/2026_03_30_090315_update_companies_table_types_and_dates.php

@@ -0,0 +1,37 @@
+<?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::table('companies', function (Blueprint $table) {
+            // 重新命名現有欄位
+            $table->renameColumn('valid_until', 'end_date');
+            
+            // 新增業務類型
+            $table->string('original_type')->default('lease')->after('code')->comment('原始類型: buyout, lease');
+            $table->string('current_type')->default('lease')->after('original_type')->comment('當前類型: buyout, lease');
+            
+            // 新增起始日
+            $table->date('start_date')->nullable()->after('status')->comment('合約起始日');
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('companies', function (Blueprint $table) {
+            $table->renameColumn('end_date', 'valid_until');
+            $table->dropColumn(['original_type', 'current_type', 'start_date']);
+        });
+    }
+};