Release v0.2.18: resizable, per-vault-persisted sidebars
Resizable, per-vault-persisted sidebars: drag the sidebar edge to resize (200–600px clamp), with width/collapsed/docked state persisted per vault across relaunches.
Fixes along the way:
- Sidebar width/collapsed/docked state was silently dropped on relaunch when the workspace had no open tabs.
- The sidebar icon bar is now part of the draggable titlebar region.
Merged in #27. Unsigned macOS build — see README's Install section for the Gatekeeper workaround.