[feat]: [feat]: Diff review interface like GitHub Desktop #458
Description
Feature Summary
Provide a GitHub Desktop–style diff/review UI with high-quality, side-by-side and inline diffs powered by a Monaco diff view.
Problem or Use Case
Today it’s hard to review and understand changes inside Stagehand; users jump to external tools to get reliable diffs, inline comments, and quick navigation for code reviews.
Proposed Solution
Embed a Monaco diff editor that supports side-by-side/inline modes, syntax highlighting, intra-line changes, keyboard nav, file tree navigation, and inline comments/notes; add staging/
discard-at-hunk-level controls and a compact toolbar for toggling whitespace, wrap, and view modes; ensure fast rendering on large files.
Alternatives Considered
Keep using external diff tools (GitHub Desktop, VS Code) to review changes; copy patches manually.
Additional Context
No response