- Set diffAlgorithm to 'legacy' for Monaco DiffEditor
- Add maxComputationTime of 10s to avoid UI freeze on huge files
This addresses the issue where sessions with large JSON files (50k-100k+ lines)
would cause the UI to freeze. The 'legacy' algorithm is faster than 'advanced'
for large files, similar to VSCode's workaround for the same issue.
See: https://github.com/microsoft/vscode/issues/184037