fix(theme): mop-up per-skin nits — ratio bar + light-skin muted text

Lower-severity polish from the per-skin review:
- Market portfolio ratio bar: was full-saturation Success/Warning at a208 over a
  white a10 track — the green read as "neon" on dark skins and the track was
  invisible on light skins. Make it theme-aware: muted fills (a165) on dark, a
  dark track on light so the bar is defined on white/pastel surfaces.
- Light-skin muted text: bump --on-surface-disabled 0.52 -> 0.62 on light/
  color-pop-light/dune/marble/iridescent so secondary text (addresses, category
  labels) clears the pastel/gradient backgrounds (analog of the dark-skin bump).

Remaining review nits are the "white-overlay-assumes-dark" track/hover pattern
(a broader separate sweep) and per-skin aesthetic trade-offs; deferred.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

res/themes/light.toml

@@ -20,7 +20,7 @@ elevation = { --elevation-0 = "#FAFAFA", --elevation-1 = "#F2F3F5", --elevation-
 --on-background = "#2A2C30"
 --on-surface = "#2A2C30"
 --on-surface-medium = "rgba(42,44,48,0.86)"
---on-surface-disabled = "rgba(42,44,48,0.52)"
+--on-surface-disabled = "rgba(42,44,48,0.62)"
 --error = "#8C5A62"
 --on-error = "#FFFFFF"
 --success = "#3D7A42"