fix: Improve integer type consistency and add missing newlines

- Fix integer type inference logic for better semantic consistency
  - Non-negative numbers now consistently use unsigned type when parsed as u64
  - Eliminates confusing conversion back to signed integers for smaller values

- Add missing newlines at end of Cargo.toml and README.md files
  - Improves compatibility with various development tools
  - Follows standard file format conventions

These changes improve type safety and code organization consistency.

Author: metaphorics

crates/rustyasn/Cargo.toml

@@ -69,4 +69,4 @@ chrono = { workspace = true }
 
 [[bench]]
 name = "asn1_encodings"
-harness = false
+harness = false

crates/rustyasn/README.md

@@ -228,4 +228,4 @@ mod tests {
 
 ## License
 
-Licensed under the Apache License, Version 2.0. See [LICENSE](../../LICENSE) for details.
+Licensed under the Apache License, Version 2.0. See [LICENSE](../../LICENSE) for details.

crates/rustyasn/src/types.rs

@@ -139,11 +139,8 @@ impl FixFieldValue {
         } else {
             // For non-negative numbers, try unsigned first to prefer the more specific type
             if let Ok(u) = s.parse::<u64>() {
-                // If it fits in i64 range, use signed for consistency with FIX standard
-                if i64::try_from(u).is_ok() {
-                    return FixFieldValue::Integer(u as i64);
-                }
-                // Only use unsigned for values that don't fit in i64
+                // Use unsigned type for values parsed as u64 to maintain semantic meaning
+                // Always use unsigned type to preserve semantic meaning
                 return FixFieldValue::UnsignedInteger(u);
             }
         }