feat(notification): 實作通知輪詢與優化顯示名稱

- 新增通知輪詢 API 與前端自動更新機制
- 修正生產工單單號格式為 PRO-YYYYMMDD-XX
- 確保通知顯示實際建立者名稱而非系統

database/migrations/tenant/2026_02_12_170000_create_notifications_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('notifications', function (Blueprint $table) {
+            $table->uuid('id')->primary();
+            $table->string('type');
+            $table->morphs('notifiable');
+            $table->text('data');
+            $table->timestamp('read_at')->nullable();
+            $table->timestamps();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('notifications');
+    }
+};