workspace_pane

Multi-base index health, errors, and activity — without duplicating the full Index tab in index_panel.
- workspace_base_picker: choose the active base; do not render a full always-visible base list.
- For the selected base: state badge, sync progress ( processed / total + current file ), idea / edge counts, global and per-file errors, recent activity.
- Clickable file issue list opens the source location in the editor.
- Refresh / cancel in-flight sync / clear & rebuild for the selected base ( or all ); " Open index tab " hands off to ideas-summary-panel.ts with that base selected.
- When no bases exist: empty state with Create Base CTA ( create_base_onboarding ).
Non-blocking sync UX: nonblocking_index.
Implemented by WorkspacePane.svelte.

Interactive page: workspace_pane