Add federation self-testing

vona/__main__.py

@@ -2,7 +2,9 @@ from flask import Flask, jsonify, request, redirect
 import vona.globals as globals
 from datetime import datetime
 import vona.config as config
+import threading
 import logging
+import os
 
 from vona.federation import server
 from vona.custom import custom
@@ -100,4 +102,16 @@ async def client():
 	})
 
 
+def federation_self_test():
+	try:
+		resp = globals.http_client.get(f"https://{config.server_name}/.well-known/matrix/server")
+		resp.raise_for_status()
+		print("[INFO] Federation self-test OK")
+	except Exception as e:
+		print(f"[FATL] Federation self-test failed: {e}")
+		os._exit(1)
+
+threading.Thread(target=federation_self_test).start()
+
+
 app.run(host=config.addr, port=config.port)