feat: add Synology NAS, Home Assistant monitoring, multi-channel notifications

New tabs:
- Synology NAS: CPU, RAM, temp, volumes, VMs, Docker containers
- Home Assistant: sensors, automations, persons, climate, battery, doors

New features:
- Personalized PC agent download with custom name
- Notification settings: per-category Telegram/Email/WhatsApp toggles
- Email via SMTP, WhatsApp via CallMeBot API
- Test notification buttons for each channel
- Unified notifier replaces direct Telegram calls in alerter

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/services/notifier.py

@@ -0,0 +1,147 @@
+"""Unified notification sender: Telegram, Email, WhatsApp (CallMeBot)."""
+
+import asyncio
+import logging
+import smtplib
+from email.mime.text import MIMEText
+from email.mime.multipart import MIMEMultipart
+from typing import Optional
+
+import aiohttp
+
+from server.config import load_settings
+
+logger = logging.getLogger(__name__)
+
+
+async def send_telegram(message: str, parse_mode: str = "Markdown"):
+    """Send message via Telegram bot."""
+    settings = load_settings()
+    token = settings.get("telegram_bot_token")
+    chat_id = settings.get("telegram_chat_id")
+    if not token or not chat_id:
+        return False
+
+    try:
+        async with aiohttp.ClientSession() as session:
+            url = f"https://api.telegram.org/bot{token}/sendMessage"
+            async with session.post(url, json={
+                "chat_id": chat_id,
+                "text": message,
+                "parse_mode": parse_mode,
+            }) as resp:
+                return resp.status == 200
+    except Exception as e:
+        logger.error(f"Telegram send error: {e}")
+        return False
+
+
+async def send_email(subject: str, body: str):
+    """Send email via SMTP."""
+    settings = load_settings()
+    smtp_host = settings.get("smtp_host", "")
+    smtp_port = int(settings.get("smtp_port", 587))
+    smtp_user = settings.get("smtp_user", "")
+    smtp_password = settings.get("smtp_password", "")
+    email_to = settings.get("email_to", "")
+
+    if not all([smtp_host, smtp_user, smtp_password, email_to]):
+        return False
+
+    try:
+        msg = MIMEMultipart()
+        msg["From"] = smtp_user
+        msg["To"] = email_to
+        msg["Subject"] = f"🖥 VPS Monitor: {subject}"
+
+        # HTML body
+        html = f"""
+        <div style="font-family:Arial,sans-serif;max-width:600px;margin:0 auto;
+                    background:#1a1a3e;color:#e8e8ff;padding:24px;border-radius:12px">
+            <h2 style="color:#6366f1;margin-bottom:16px">🖥 VPS Monitoring</h2>
+            <div style="background:#0f0f23;padding:16px;border-radius:8px;
+                        border-left:4px solid #6366f1;margin-bottom:16px">
+                {body.replace(chr(10), '<br>')}
+            </div>
+            <p style="color:#a0a0cc;font-size:12px">Автоматическое уведомление VPS Monitoring</p>
+        </div>
+        """
+        msg.attach(MIMEText(html, "html"))
+
+        loop = asyncio.get_event_loop()
+        await loop.run_in_executor(None, _smtp_send, smtp_host, smtp_port, smtp_user, smtp_password, email_to, msg)
+        return True
+    except Exception as e:
+        logger.error(f"Email send error: {e}")
+        return False
+
+
+def _smtp_send(host, port, user, password, to, msg):
+    """Blocking SMTP send (run in executor)."""
+    with smtplib.SMTP(host, port, timeout=15) as server:
+        server.starttls()
+        server.login(user, password)
+        server.sendmail(user, to, msg.as_string())
+
+
+async def send_whatsapp(message: str):
+    """Send WhatsApp message via CallMeBot API.
+
+    Setup: User sends "I allow callmebot to send me messages" to
+    +34 644 71 85 23 on WhatsApp, gets apikey.
+    Store phone + apikey in settings.
+    """
+    settings = load_settings()
+    wa_phone = settings.get("whatsapp_phone", "")
+    wa_apikey = settings.get("whatsapp_apikey", "")
+
+    if not wa_phone or not wa_apikey:
+        return False
+
+    try:
+        # Clean message for URL
+        clean_msg = message.replace("**", "*")
+        async with aiohttp.ClientSession() as session:
+            url = "https://api.callmebot.com/whatsapp.php"
+            params = {
+                "phone": wa_phone,
+                "text": clean_msg,
+                "apikey": wa_apikey,
+            }
+            async with session.get(url, params=params) as resp:
+                return resp.status == 200
+    except Exception as e:
+        logger.error(f"WhatsApp send error: {e}")
+        return False
+
+
+async def send_notification(message: str, subject: str = "Alert", category: str = "servers"):
+    """Send notification via all enabled channels for given category.
+
+    Categories: servers, pc, synology, ha
+    Settings key: notify_{category}_{channel} = true/false
+    Channels: telegram, email, whatsapp
+    """
+    from datetime import datetime
+    from server.api.auth_routes import mute_until
+
+    # Check global mute
+    if mute_until and datetime.now() < mute_until:
+        return
+
+    settings = load_settings()
+    notify_prefs = settings.get("notifications", {})
+
+    # Default: telegram enabled for all
+    cat_prefs = notify_prefs.get(category, {"telegram": True, "email": False, "whatsapp": False})
+
+    tasks = []
+    if cat_prefs.get("telegram", True):
+        tasks.append(send_telegram(message))
+    if cat_prefs.get("email", False):
+        tasks.append(send_email(subject, message))
+    if cat_prefs.get("whatsapp", False):
+        tasks.append(send_whatsapp(message))
+
+    if tasks:
+        await asyncio.gather(*tasks, return_exceptions=True)