Wire seller push notifications with FCM, inbox API, and payment milestones.

Sellers get instant payment alerts on Android; withdrawals respect payout prefs.

Co-authored-by: Cursor <cursoragent@cursor.com>

database/migrations/2026_06_11_120000_create_user_push_tokens_table.php

@@ -0,0 +1,36 @@
+<?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::create('user_push_tokens', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('user_id')->constrained()->cascadeOnDelete();
+            $table->string('token', 512)->unique();
+            $table->string('platform', 32)->default('android');
+            $table->string('device_name')->nullable();
+            $table->timestamp('last_seen_at')->nullable();
+            $table->timestamps();
+
+            $table->index(['user_id', 'updated_at']);
+        });
+
+        Schema::table('users', function (Blueprint $table) {
+            $table->timestamp('last_app_active_at')->nullable()->after('remember_token');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('users', function (Blueprint $table) {
+            $table->dropColumn('last_app_active_at');
+        });
+
+        Schema::dropIfExists('user_push_tokens');
+    }
+};