[FEAT] 優化帳號管理授權顯示邏輯與 UI 樣式一致性

database/factories/Machine/MachineFactory.php

@@ -17,6 +17,7 @@ class MachineFactory extends Factory
             'status' => fake()->randomElement(['online', 'offline', 'error']),
             'temperature' => fake()->randomFloat(2, 2, 10),
             'firmware_version' => 'v' . fake()->randomElement(['1.0.0', '1.1.2', '2.0.1']),
+            'serial_no' => 'SN-' . strtoupper(fake()->unique()->bothify('??###?')),
             'last_heartbeat_at' => fake()->dateTimeBetween('-1 day', 'now'),
         ];
     }

database/migrations/2026_03_23_093421_create_machine_user_table.php

@@ -0,0 +1,31 @@
+<?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('machine_user', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('machine_id')->constrained()->onDelete('cascade');
+            $table->foreignId('user_id')->constrained()->onDelete('cascade');
+            $table->timestamps();
+
+            $table->unique(['machine_id', 'user_id']); // Ensure uniqueness
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('machine_user');
+    }
+};