Fix Android app connection and timeout issues

Add proper timeout configuration to OkHttpClient (30s connect/read/write)
Update OkHttp logging-interceptor to 4.12.0 to match OkHttp version
Improve error messages to show server URL for debugging
Configure backend to listen on all interfaces (0.0.0.0)
Remove EdgeToEdge calls that interfered with layout

backend/src/main/resources/application.yml

@@ -36,6 +36,7 @@ spring:
 
 server:
   port: ${SERVER_PORT:8080}
+  address: ${SERVER_ADDRESS:0.0.0.0}
   servlet:
     context-path: /