v0.21.0

Sub-agents

• New sidebar hierarchy for sub-agents, including connector lines and better expansion for completed runs.
• Active sub-agents animate in the sidebar.
• The sub-agent toggle moved to the kebab menu.
• Double-click now always renames.
• Added support for "Best of N" type sub-agent launches where the parent launch N sub-agents with the same prompt and synthesizes the best path forward

Analytics

• Added a save action for chat analytics results.
• Added a saved analytics panel SQL editor.

Quality of Life

• Better handling of edited messages before stream start.
• Reduced false interruptions by not treating slow stream starts as interruptions.
• Todos are session-scoped now, so they survive stream interruptions better.
  • Completed todo lists are cleared more reliably after final streams.
  • Pinned todo panels now auto-collapse more appropriately.
• Better wide-touch sidebar interactions.
• Mux now surfaces MCP server startup failures instead of failing more silently.
• Fixed some cost display/reset issues around Codex OAuth and forked workspaces.