fix: allow read tool to read invalid utf char based file

crates/forge_fs/src/read_range.rs

@@ -45,9 +45,10 @@ impl crate::ForgeFS {
         }
 
         // Read file content
-        let content = tokio::fs::read_to_string(path_ref)
+        let content = tokio::fs::read(path_ref)
             .await
             .with_context(|| format!("Failed to read file content from {}", path_ref.display()))?;
+        let content = String::from_utf8_lossy(&content);
         if start_line < 2 && content.is_empty() {
             // If the file is empty, return empty content
             return Ok((String::new(), FileInfo::new(start_line, end_line, 0)));
@@ -74,7 +75,7 @@ impl crate::ForgeFS {
 
         // Extract requested lines
         let result_content = if start_pos == 0 && end_pos == total_lines - 1 {
-            content // Return full content if requesting entire file
+            content.to_string() // Return full content if requesting entire file
         } else {
             lines[start_pos as usize..=end_pos as usize].join("\n")
         };
@@ -173,4 +174,16 @@ mod test {
 
         Ok(())
     }
+
+    #[tokio::test]
+    async fn test_invalid_utf8_handling() -> Result<()> {
+        let content = b"Hello world!\nValid line\n\xFF\xFE\xFD Invalid UTF-8\nAnother valid line";
+        let file = tempfile::NamedTempFile::new()?;
+        fs::write(file.path(), content).await?;
+
+        // Attempt to read the file shouldn't fail with invalid UTF-8 error
+        let result = crate::ForgeFS::read_range_utf8(&file.path(), 1, 4).await;
+        assert!(result.is_ok());
+        Ok(())
+    }
 }