Runner v0.3.3

Sidebar tab accordion

Multi-pane tabs now read as one unit in the sidebar CHAT list. A tab with 2+ chats collapses into an accordion group — a header (disclosure chevron · split icon · pane-count badge) over its member chats, indented under a rail. Single chats stay flat leaf rows, so single- vs multi-pane is legible at a glance.

• Collapse to tidy — click the chevron/header to fold a group away; the state persists per tab across restarts. The active on-screen tab always stays expanded.
• Still one tab — the active tab keeps its accent rail + focused-pane marker; pin, rename, and the row context menu work exactly as before, and pinning a group pins every member together.
• Frontend-only display grouping — no backend changes (impl 0023).