webclient: V1–V3 — visible kit 1.0 pass on input bar, sidebar and chat cards ...

- Input row shaped exactly like a kit input (panel-muted, 2px muted
  border, 3px radius, hover/focus-within states)
- Sidebar: uppercase NAVI logo, row separators, session names in
  text-light, uppercase chat header title
- Chat surfaces: 6px radius on thinking/plan/tool/subagent/summary
  cards, summary card switched to muted border + info accent stripe,
  user bubble radius, pill radius on file pills, kit radii on
  code-block and markdown image links, 6px accent quote stripe in
  tool results
- dist rebuilt on kit 1.0