Add subscription tiers, notification preferences, and logging infrastructure

- Add database migrations for plans, subscriptions, notification preferences, and notification log tables
- Implement DispatchUserNotificationJob to handle channel resolution, daily limits, and logging (sent/tier_restricted/daily_limit)
- Add SendScheduledWhatsAppJob for scheduled notification delivery
- Create PlanFeatures service to resolve tier capabilities, check daily limits, and validate fuel

app/Http/Middleware/RequiresFeature.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace App\Http\Middleware;
+
+use App\Services\PlanFeatures;
+use Closure;
+use Illuminate\Http\Request;
+use Symfony\Component\HttpFoundation\Response;
+
+class RequiresFeature
+{
+    /**
+     * Handle an incoming request.
+     *
+     * @param  Closure(Request): (Response)  $next
+     */
+    public function handle(Request $request, Closure $next, string $feature): Response
+    {
+        $user = $request->user();
+
+        if (! $user || ! PlanFeatures::for($user)->can($feature)) {
+            return response()->json([
+                'error' => 'upgrade_required',
+                'feature' => $feature,
+            ], Response::HTTP_FORBIDDEN);
+        }
+
+        return $next($request);
+    }
+}