fix: telegram webhook payload format and pbs connection issues (fixes #294)

- add proper telegram bot api support with chat_id and text fields
- fix frontend pbs red dot display (was checking 'error' instead of 'unhealthy')
- fix qemu guest agent memory reporting (fallback to mem when freemem is 0)
- extract chat_id from telegram webhook urls when present

internal/api/notifications.go

@@ -337,8 +337,17 @@ func (h *NotificationHandlers) TestWebhook(w http.ResponseWriter, r *http.Reques
 	}
 	if err := json.Unmarshal(bodyBytes, &serviceCheck); err == nil && serviceCheck.Service != "" {
 		webhook.Service = serviceCheck.Service
+		// Also set it in the basic webhook for consistency
+		basicWebhook.Service = serviceCheck.Service
+		webhook.WebhookConfig.Service = serviceCheck.Service
 	}
 	
+	log.Info().
+		Str("service", webhook.Service).
+		Str("url", webhook.URL).
+		Str("name", webhook.Name).
+		Msg("Testing webhook")
+	
 	// Get template for the service
 	templates := notifications.GetWebhookTemplates()
 	for _, tmpl := range templates {
@@ -350,6 +359,7 @@ func (h *NotificationHandlers) TestWebhook(w http.ResponseWriter, r *http.Reques
 			for k, v := range tmpl.Headers {
 				webhook.Headers[k] = v
 			}
+			log.Info().Str("service", webhook.Service).Msg("Found template for service")
 			break
 		}
 	}

internal/notifications/notifications.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"net/url"
 	"strings"
 	"sync"
 	"text/template"
@@ -466,18 +467,18 @@ func (n *NotificationManager) sendWebhook(webhook WebhookConfig, alert *alerts.A
 	var jsonData []byte
 	var err error
 	
-	// Check if this is a Discord webhook and use the proper template
-	if webhook.Service == "discord" {
+	// Check if this is a service-specific webhook and use the proper template
+	if webhook.Service == "discord" || webhook.Service == "telegram" {
 		// Convert to enhanced webhook to use template
 		enhanced := EnhancedWebhookConfig{
 			WebhookConfig: webhook,
-			Service:       "discord",
+			Service:       webhook.Service,
 		}
 		
-		// Get Discord template
+		// Get service template
 		templates := GetWebhookTemplates()
 		for _, tmpl := range templates {
-			if tmpl.Service == "discord" {
+			if tmpl.Service == webhook.Service {
 				enhanced.PayloadTemplate = tmpl.PayloadTemplate
 				break
 			}
@@ -485,13 +486,26 @@ func (n *NotificationManager) sendWebhook(webhook WebhookConfig, alert *alerts.A
 		
 		// Prepare data and generate payload
 		data := n.prepareWebhookData(alert, nil)
+		
+		// For Telegram, extract chat_id from URL if present
+		if webhook.Service == "telegram" && strings.Contains(webhook.URL, "chat_id=") {
+			// Extract chat_id from URL query params
+			if u, err := url.Parse(webhook.URL); err == nil {
+				chatID := u.Query().Get("chat_id")
+				if chatID != "" {
+					data.ChatID = chatID
+				}
+			}
+		}
+		
 		jsonData, err = n.generatePayloadFromTemplate(enhanced.PayloadTemplate, data)
 		if err != nil {
 			log.Error().
 				Err(err).
 				Str("webhook", webhook.Name).
+				Str("service", webhook.Service).
 				Str("alertID", alert.ID).
-				Msg("Failed to generate Discord payload")
+				Msg("Failed to generate webhook payload")
 			return
 		}
 	} else {

internal/notifications/webhook_enhanced.go

@@ -51,6 +51,7 @@ type WebhookPayloadData struct {
 	CustomFields map[string]interface{}
 	AlertCount   int
 	Alerts       []*alerts.Alert // For grouped alerts
+	ChatID       string           // For Telegram webhooks
 }
 
 // SendEnhancedWebhook sends a webhook with template support

internal/notifications/webhook_templates.go

@@ -45,6 +45,20 @@ func GetWebhookTemplates() []WebhookTemplate {
 			}`,
 			Instructions: "1. In Discord, go to Server Settings > Integrations > Webhooks\n2. Create a new webhook and copy the URL\n3. Paste the URL here (format: https://discord.com/api/webhooks/...)",
 		},
+		{
+			Service:    "telegram",
+			Name:       "Telegram Bot",
+			URLPattern: "https://api.telegram.org/bot{bot_token}/sendMessage",
+			Method:     "POST",
+			Headers:    map[string]string{"Content-Type": "application/json"},
+			PayloadTemplate: `{
+				"chat_id": "{{.ChatID}}",
+				"text": "🚨 *Pulse Alert: {{.Level | title}}*\n\n{{.Message}}\n\n📊 *Details:*\n• Resource: {{.ResourceName}}\n• Node: {{.Node}}\n• Type: {{.Type | title}}\n• Value: {{printf "%.1f" .Value}}%\n• Threshold: {{printf "%.0f" .Threshold}}%\n• Duration: {{.Duration}}\n\n🔗 [View in Pulse]({{.Instance}})",
+				"parse_mode": "Markdown",
+				"disable_web_page_preview": true
+			}`,
+			Instructions: "1. Create a bot with @BotFather on Telegram\n2. Get your bot token\n3. Get your chat ID by messaging the bot and visiting: https://api.telegram.org/bot<YOUR_BOT_TOKEN>/getUpdates\n4. URL format: https://api.telegram.org/bot<BOT_TOKEN>/sendMessage",
+		},
 		{
 			Service:    "slack",
 			Name:       "Slack Incoming Webhook",