Improve error handling, ensure robust defaults, and eliminate unsafe unwraps/expectations across modules.

Software/MainBoard/rust/src/webserver/backup_manager.rs

@@ -34,7 +34,8 @@ where
     )
     .await?;
 
-    conn.write_all(serde_json::to_string(&backup)?.as_bytes()).await?;
+    conn.write_all(serde_json::to_string(&backup)?.as_bytes())
+        .await?;
     Ok(Some(200))
 }
 
@@ -44,7 +45,7 @@ pub(crate) async fn backup_config<T, const N: usize>(
 where
     T: Read + Write,
 {
-    let input = read_up_to_bytes_from_request(conn, Option::None).await?;
+    let input = read_up_to_bytes_from_request(conn, Some(4096)).await?;
     let mut board = BOARD_ACCESS.get().await.lock().await;
     let config_to_backup = serde_json::from_slice(&input)?;
     board.board_hal.backup_config(&config_to_backup).await?;
@@ -70,10 +71,9 @@ where
     let mut board = BOARD_ACCESS.get().await.lock().await;
     let info = board.board_hal.backup_info().await;
 
-
     let json = match info {
         Ok(h) => {
-            let timestamp = DateTime::from_timestamp_millis(h.timestamp).unwrap();
+            let timestamp = DateTime::from_timestamp_millis(h.timestamp).unwrap_or_default();
             let wbh = WebBackupHeader {
                 timestamp: timestamp.to_rfc3339(),
                 size: h.size,