activity_bar

The extension should provide an activity bar sidebar for editor-adjacent requirement context per local_graph_view.
UI is implemented as Svelte webview panes per core.rq, not as a long-lived tree of static rows.
The host loads slices from the index via local_graph_analysis and forwards editor focus through activity-bar-webview-provider.ts and activity-bar-data-service.ts.
Panes should be performance conscious: capped neighbourhoods, lazy cytoscape mount, debounced cursor updates — same discipline as webview.
Workspace-wide tables, full layout controls, and unconstrained graph dumps belong in Ideas Summary per ideas_summary; panes link out with prefilled state instead of duplicating those views.

Interactive page: activity_bar