fix(volume): preserve exact byte counts with B suffix

Author: erijo

core/src/volume/utils.rs

@@ -42,7 +42,7 @@ pub fn parse_size_string(size_str: &str) -> VolumeResult<u64> {
 
 	// Linux `df -B1` emits integer byte counts. Parse those directly so values above
 	// f64's exact-integer range retain all bits of precision.
-	if unit.is_empty() && !number_part.contains('.') {
+	if (unit.is_empty() || unit.eq_ignore_ascii_case("B")) && !number_part.contains('.') {
 		return number_part
 			.parse::<u64>()
 			.map_err(|_| VolumeError::InvalidData(format!("Invalid size: {}", size_str)));
@@ -360,6 +360,10 @@ mod tests {
 			parse_size_string("9007199254740993").unwrap(),
 			9_007_199_254_740_993
 		);
+		assert_eq!(
+			parse_size_string("9007199254740993B").unwrap(),
+			9_007_199_254_740_993
+		);
 		assert_eq!(
 			parse_size_string("1,5G").unwrap(),
 			(1.5 * 1024.0 * 1024.0 * 1024.0) as u64