Muat turun codeg 0.21.6

- feat(git-log): A rebuilt Commit history tab. Virtualized and paged for long histories, with branch and author filters, a pushed/not-pushed marker on every commit, and your filter choices remembered per folder.
- feat(sidebar): Group sessions by git worktree. Turn on "Show worktree folders" to nest each worktree under its repo as a collapsible, branch-labelled sub-group. On by default now, alongside "Show completed."
- feat(delegation): Mention an agent with @ to hand it the work. Naming a sub-agent in your message now delegates that work straight to it — one delegation per agent named.
- feat(chat): View a diff from a reply's changed files. Each modified file now has a View Diff button that opens its diff in an editor tab, on web and desktop.
- feat(layout): Session stats on mobile. The mobile status bar now shows your session stats on the left.
- fix(chat): No more phantom tool cards after a turn ends. Empty tool calls left by interrupted or retried turns no longer resurface and inflate the tool-group and poll cards.
- fix(messages): The focus ring follows your keyboard, not your mouse. Clicking a message no longer leaves a focus outline; keyboard navigation still shows one. Thanks to @youxikexue (#338).
- fix(chat): A tidier connection indicator. It now aligns with the send button and uses a muted colour when connected instead of a green heart.
- fix(layout): No stray scrollbar on the branch selector. The popup now sizes to its rows, so filtered lists have no leftover scrollbar or empty space.
- chore(acp): Refreshed the bundled agent versions. Claude Code 0.61.0, Gemini 0.52.0, CodeBuddy 2.126.0, Kimi Code 0.29.0, Grok 0.2.111, and Cursor 2026.07.20.