feat: add incoming webhook API support with configurable endpoints

- Implemented the incoming webhook API to handle alerts from external applications.
- Added configuration options for webhook listening address, port, and endpoints in config.go.
- Created WebhookReceiverConfig and WebhookEndpointConfig structures to manage webhook settings.
- Developed WebhookHandler to process incoming requests, validate tokens, and deliver alerts to specified channels.
- Enhanced existing controller interfaces to support alert delivery.
- Updated message rendering to respect Markdown settings for different channels.
- Added tests for webhook functionality and ensured proper error handling.

internal/controller/trigger.go

@@ -43,10 +43,10 @@ func (m *Manager) Trigger(cmd Command, trustedGroups, admins []string, listenMet
 // RouteCommand processes a parsed bot command and returns the response text.
 // The actual command execution for every pipe is unified here.
 func (m *Manager) RouteCommand(cmd Command) (string, error) {
-	if cmd.Source == "telegram"{
+	if cmd.Source == "telegram" {
 		switch cmd.Command {
 		case "start":
-			return telegram_handleStart()
+			return telegram_handleStart(cmd)
 		}
 	}
 	switch cmd.Command {