Bash tool can show a diff of files it changed

What

• A new bashEditDiffEnabled settings.json key (and CLAUDE_CODE_BASH_EDIT_DIFF environment variable override) controls whether the Bash tool computes and shows a diff of files changed by a shell command.
• Under the hood, this is backed by git-based snapshots taken before and after a Bash command (via a sandboxed git wrapper), with filesystem watchers (inotify on Linux, fs.watch elsewhere) to catch changes made outside the tracked diff.
• The result appears as bashEditDiff on the Bash tool's result, and PostToolUse hooks for Bash now receive the list of changed files in tool_response too.
• It's skipped for destructive git operations run via Bash (checkout, switch, stash, pull, merge, rebase, reset, restore, clean, cherry-pick, revert), and reports status through telemetry (bash_edit_diff, and unavailable/interrupted variants).
• Outside auto or bypassPermissions modes, only a user, flag, or policy setting can turn this on; the docs describe it as on by default when the Bash tool handles file edits.

Why This lets Claude Code (and hooks watching its actions) see exactly what a shell command changed on disk, without having to separately diff the repo, making Bash tool calls more transparent and auditable.