[FEAT] 客戶管理欄位（客戶代號、起始日）非必填化

1. 新增遷移檔將 companies.code 改為 nullable 並增加長度至 100，解決刪除時字串過長的問題。
2. 修改 CompanyController 驗證邏輯，允許 code 與 start_date 為空。
3. 更新前端公司管理頁面，移除 code 與 start_date 的必填限制與 UI 標記。

app/Http/Controllers/Admin/CompanyController.php

@@ -48,13 +48,13 @@ class CompanyController extends Controller
     {
         $validated = $request->validate([
             'name' => 'required|string|max:255',
-            'code' => 'required|string|max:50|unique:companies,code',
+            'code' => 'nullable|string|max:50|unique:companies,code',
             'original_type' => 'required|string|in:buyout,lease',
             'tax_id' => 'nullable|string|max:50',
             'contact_name' => 'nullable|string|max:255',
             'contact_phone' => 'nullable|string|max:50',
             'contact_email' => 'nullable|email|max:255',
-            'start_date' => 'required|date',
+            'start_date' => 'nullable|date',
             'end_date' => 'nullable|date',
             'warranty_start_date' => 'nullable|date',
             'warranty_end_date' => 'nullable|date',
@@ -158,13 +158,13 @@ class CompanyController extends Controller
     {
         $validated = $request->validate([
             'name' => 'required|string|max:255',
-            'code' => 'required|string|max:50|unique:companies,code,' . $company->id,
+            'code' => 'nullable|string|max:50|unique:companies,code,' . $company->id,
             'current_type' => 'required|string|in:buyout,lease',
             'tax_id' => 'nullable|string|max:50',
             'contact_name' => 'nullable|string|max:255',
             'contact_phone' => 'nullable|string|max:50',
             'contact_email' => 'nullable|email|max:255',
-            'start_date' => 'required|date',
+            'start_date' => 'nullable|date',
             'end_date' => 'nullable|date',
             'warranty_start_date' => 'nullable|date',
             'warranty_end_date' => 'nullable|date',

database/migrations/2026_05_15_164013_make_company_code_nullable_in_companies_table.php

@@ -0,0 +1,28 @@
+<?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) {
+            $table->string('code', 100)->nullable()->change();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('companies', function (Blueprint $table) {
+            $table->string('code', 20)->nullable(false)->change();
+        });
+    }
+};

resources/views/admin/companies/index.blade.php

@@ -795,8 +795,8 @@
                             </div>
                             <div class="space-y-2">
                                 <label class="text-xs font-black text-slate-500 uppercase tracking-widest pl-1">{{
-                                    __('Company Code') }} <span class="text-rose-500 ml-0.5">*</span></label>
+                                    __('Company Code') }}</label>
-                                <input type="text" name="code" x-model="currentCompany.code" required
+                                <input type="text" name="code" x-model="currentCompany.code"
                                     class="luxury-input w-full" placeholder="{{ __('e.g. TWSTAR') }}">
                             </div>
                         </div>
@@ -811,8 +811,8 @@
                             <div class="grid grid-cols-2 gap-3" x-show="currentCompany.current_type === 'lease'">
                                 <div class="space-y-2">
                                     <label class="text-xs font-black text-slate-500 uppercase tracking-widest pl-1">{{
-                                        __('Start Date') }} <span class="text-rose-500 ml-0.5">*</span></label>
+                                        __('Start Date') }}</label>
-                                    <input type="date" name="start_date" x-model="currentCompany.start_date" :required="currentCompany.current_type === 'lease'"
+                                    <input type="date" name="start_date" x-model="currentCompany.start_date"
                                         class="luxury-input w-full px-2">
                                 </div>
                                 <div class="space-y-2">