Add favicon handler and heartbeat LED blink.

This keeps the UI console clean and makes device status visible.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/main.py

@@ -2,6 +2,7 @@ import asyncio
 import gc
 import json
 import machine
+from machine import Pin
 from microdot import Microdot, send_file
 from microdot.websocket import with_websocket
 from microdot.session import Session
@@ -23,6 +24,7 @@ from models.espnow import ESPNow
 
 async def main(port=80):
     settings = Settings()
+    print(settings)
     print("Starting")
 
     sta = network.WLAN(network.STA_IF)
@@ -72,6 +74,11 @@ async def main(port=80):
         """Serve the settings page."""
         return send_file('templates/settings.html')
     
+    # Favicon: avoid 404 in browser console (no file needed)
+    @app.route('/favicon.ico')
+    def favicon(request):
+        return '', 204
+
     # Static file route
     @app.route("/static/<path:path>")
     def static_handler(request, path):
@@ -107,10 +114,20 @@ async def main(port=80):
     #wdt = machine.WDT(timeout=10000)
     #wdt.feed()
 
+    # Initialize heartbeat LED (XIAO ESP32S3 built-in LED on GPIO 21)
+  
+    led = Pin(21, Pin.OUT)
+
+
+    led_state = False
+
     while True:
         gc.collect()
         for i in range(60):
             #wdt.feed()
+            # Heartbeat: toggle LED every 500 ms
+           
+            led.value(not led.value())
             await asyncio.sleep_ms(500)
     # cleanup before ending the application