feat: Add notification services for Email, Telegram, and WhatsApp

- Implement EmailNotifier for sending batch and test notifications via email.
- Implement TelegramNotifier for sending batch and test notifications via Telegram.
- Implement WahaNotifier for sending batch and test notifications via WhatsApp using WAHA API.
- Create migration for client_categories table and update clients table to include category_id.
- Create migration for notification_settings table to manage notification configurations.
- Add ClientCategorySeeder to populate default client categories.
- Create manifest.json for PWA support.
- Implement service worker (sw.js) for caching static assets and offline support.
- Add edit event view for modifying scheduled events.
- Create search results view for displaying search queries.
- Develop notification settings view for configuring notification channels and triggers.

app/Services/Notifications/TelegramNotifier.php

@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Services\Notifications;
+
+use App\Models\NotificationSetting;
+use Illuminate\Support\Facades\Http;
+
+class TelegramNotifier
+{
+    public function sendBatch(NotificationSetting $setting, array $messages): void
+    {
+        foreach ($messages as $message) {
+            $this->send($setting, $message);
+        }
+    }
+
+    public function sendTest(NotificationSetting $setting): void
+    {
+        $this->send(
+            $setting,
+            "🐱 *KOL Manager — Test Notification*\n\nYour Telegram channel is configured correctly! 🎉"
+        );
+    }
+
+    private function send(NotificationSetting $setting, string $text): void
+    {
+        $config   = $setting->config ?? [];
+        $botToken = $config['bot_token'] ?? null;
+        $chatId   = $config['chat_id'] ?? null;
+
+        if (! $botToken || ! $chatId) {
+            throw new \RuntimeException('Telegram bot_token and chat_id are required.');
+        }
+
+        $response = Http::timeout(10)->post(
+            "https://api.telegram.org/bot{$botToken}/sendMessage",
+            [
+                'chat_id'    => $chatId,
+                'text'       => $text,
+                'parse_mode' => 'Markdown',
+            ]
+        );
+
+        if (! $response->successful()) {
+            throw new \RuntimeException('Telegram API error: ' . $response->body());
+        }
+    }
+}