Sovereign Ledger 0.4.0-dev (build 46)

feat(ui): platform-split nav + light-mode palettes

Bottom nav now branches per platform — iOS gets the liquid-glass
capsule, Android returns to its classic design (as before the glass):

• iOS: floating capsule over full-bleed content (overlay Box root);
  bar/clearance tuning unchanged
• Android: Scaffold bottomBar slot restored — content stops at the
  bar, no glass peek-through; square corners (radius removed), total
  height 117→~102dp (86dp content + inset), fill = SurfaceBlur + 8%
  Steel elevation + 3% primary whisper, 1dp BorderSoft top hairline
• ledgerNavClearance() is iOS-only now (Scaffold pads Android)
• Light mode: Summer/Orchid/Forest now apply in Light (Sovereign-light
  neutrals + darkened palette accents); light GlassEdge switched to
  the dark hairline family — white vanished on light glass
• Root paints LedgerColors.Canvas (restores the background the old
  Scaffold containerColor provided; fixes Light mode)

Verified on iPhone 12 mini (iOS 26.5) and Android device, both themes.