- Restructure Pane as a tagged union over kind so checking kind narrows state - Rename session_panes_session_idx -> idx_session_panes_session for naming consistency with idx_sessions_project, idx_messages_session
- Restructure Pane as a tagged union over kind so checking kind narrows state - Rename session_panes_session_idx -> idx_session_panes_session for naming consistency with idx_sessions_project, idx_messages_session