feat: add referral

database/migrations/2026_06_06_000000_add_referral_code_to_users_table.php

@@ -0,0 +1,42 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('users', function (Blueprint $table) {
+            // Own shareable code, mirrored from approagency (source of truth).
+            if (!Schema::hasColumn('users', 'referral_code')) {
+                $table->string('referral_code', 12)->nullable()->after('identifier');
+            }
+            // Local meditation user who referred this user (resolved from approagency's referrer_uuid).
+            if (!Schema::hasColumn('users', 'referred_by')) {
+                $table->foreignId('referred_by')->nullable()->after('referral_code')
+                    ->constrained('users')->nullOnDelete();
+            }
+            // Points earned through referrals (100 per invite + 10% of friends' xp).
+            if (!Schema::hasColumn('users', 'referral_points')) {
+                $table->unsignedInteger('referral_points')->default(0)->after('referred_by');
+            }
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('users', function (Blueprint $table) {
+            if (Schema::hasColumn('users', 'referred_by')) {
+                $table->dropForeign(['referred_by']);
+                $table->dropColumn('referred_by');
+            }
+            foreach (['referral_code', 'referral_points'] as $column) {
+                if (Schema::hasColumn('users', $column)) {
+                    $table->dropColumn($column);
+                }
+            }
+        });
+    }
+};