Option to collapse file edit diffs by default (expand on demand)

Feature Request

When Claude Code edits a file via the Edit or Write tool, the diff is always displayed inline. For users who trust the changes and prefer a cleaner output, this adds visual noise.

Requested behavior: A setting (e.g., collapseDiffsByDefault: true) that collapses file edit diffs by default, with a keybinding (e.g., Ctrl+O or similar) to expand/reveal them on demand.

Current workaround: Ctrl+O toggles the verbose transcript, but that controls overall verbosity rather than specifically targeting edit diffs.

Use case: Power users who review diffs selectively rather than on every edit. The diffs would still be accessible — just collapsed until expanded via keyboard shortcut.