feat: add settings table and Setting model

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

database/migrations/2026_05_19_100058_create_settings_table.php

@@ -0,0 +1,26 @@
+<?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('settings', function (Blueprint $table) {
+            $table->id();
+            $table->string('key')->unique();
+            $table->text('value')->nullable();
+            $table->timestamps();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('settings');
+    }
+};