agent2: More efficent read file tool (#38407)

Before we were always reading the entire file into memory as a string.
Now we only read the range that is actually requested.

Release Notes:

- N/A
ca05ff89f4Ben Brandt committed on 9/18/2025, 10:05:05 AM· committed by GitHubparent9f9e806
1 file changedLine totals unavailable