webclient: polish batch — caps off, kit badge/chip in header+input, search clear closes, mobile full-bleed input, settings centered ...

- chat-header-title and sidebar logo span: remove forced uppercase
- profile badge -> GnBadge (variant per profile: secretary secondary,
  server_admin warning, developer info); custom box styles dropped
- pending file pill -> GnChip (icon + removable); image thumb stays
  app-owned (no kit image-preview component) but on kit surface look
- sidebar search clear button now also closes the field
- input-row: no yellow focus ring; on mobile full-screen width, no
  borders, inner padding carries the breathing room
- sidebar footer: without-hover removed from gear/admin/logout buttons
  — kit hover returns
- settings: header and body centered, max-width 1200px