fix: retry InfluxDB writes and notify on failure

Co-authored-by: aider (gemini/gemini-3.1-pro-preview) <aider@aider.chat>

main.py

@@ -149,11 +149,16 @@ class Sensor():
             'fields': data,
         }
 
-        try:
-            sensors_client.write_points([point])
-        except requests.exceptions.ConnectionError:
-            logging.exception('Error connecting to InfluxDB!')
-            return
+        for attempt in range(3):
+            try:
+                sensors_client.write_points([point])
+                break
+            except Exception as e:
+                logging.exception('Error writing to InfluxDB (attempt %s/3): %s', attempt + 1, e)
+                if attempt == 2:
+                    controller_message('Failed to write to InfluxDB after 3 attempts: ' + str(e))
+                    return
+                time.sleep(1)
 
         logging.info('Wrote %s data to InfluxDB: %s', self, data)