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

database/migrations/2026_04_14_110301_create_subscriptions_table.php

@@ -0,0 +1,37 @@
+<?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('subscriptions', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('user_id');
+            $table->string('type');
+            $table->string('stripe_id')->unique();
+            $table->string('stripe_status');
+            $table->string('stripe_price')->nullable();
+            $table->integer('quantity')->nullable();
+            $table->timestamp('trial_ends_at')->nullable();
+            $table->timestamp('ends_at')->nullable();
+            $table->timestamps();
+
+            $table->index(['user_id', 'stripe_status']);
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('subscriptions');
+    }
+};