docs: changelog entry for collapsible file diffs

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: brendan-kellam

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added commit diff viewer to code browser. [#1154](https://github.com/sourcebot-dev/sourcebot/pull/1154)
 - Added `/api/commits/authors` to the public API to allow fetching a list of authors for a given path and revision. [#1150](https://github.com/sourcebot-dev/sourcebot/pull/1150)
 - Added optional `path` query parameter to the `/api/diff` endpoint and `get_diff` MCP tool to restrict diffs to changes touching a specific file. [#1154](https://github.com/sourcebot-dev/sourcebot/pull/1154)
+- Added collapsible file diffs in the commit diff panel. [#1157](https://github.com/sourcebot-dev/sourcebot/pull/1157)
 
 ### Fixed
 - Bumped `postcss` to `8.5.10`. [#1155](https://github.com/sourcebot-dev/sourcebot/pull/1155)