fix(theme): per-skin legibility polish from the sweep review

Address the high-severity, systemic legibility issues found in the per-skin
screenshot review (verified across all 9 skins):

- Status pills (history): "Confirmed" text was 55%-alpha (dim); make it full
  opacity, and give status/shield pills a visible tinted fill (a48) + 1px border
  (a90) so they stop vanishing on dark-red / near-white / gradient skins.
- Console light theming: light skins now use a near-white terminal surface, and
  the log text/JsonBrace colors switch to the dark defaults in light themes (the
  schema colors are dark-terminal-authored — honor them only in dark themes) so
  text isn't pale-on-white.
- Dark-skin muted text: bump --on-surface-medium 0.85 / --on-surface-disabled
  0.58 on dragonx/dark/color-pop-dark/obsidian (obsidian addresses were ~1.1:1).
- Disabled Send button: the disabled fill was hardcoded white (invisible on
  light skins) — use a dark overlay in light themes.
- Light-skin inputs: stronger frame fill + border color and a 1px frame border
  for light themes so fields (and buttons) have defined boundaries on white/
  pastel surfaces.

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

res/themes/ui.toml

@@ -37,8 +37,8 @@ images = { background_image = "backgrounds/texture/drgx_bg.png", logo = "logos/l
 --on-secondary = "#000000"
 --on-background = "#F0E0D8"
 --on-surface = "#F0E0D8"
---on-surface-medium = "rgba(240,224,216,0.7)"
---on-surface-disabled = "rgba(240,224,216,0.44)"
+--on-surface-medium = "rgba(240,224,216,0.85)"
+--on-surface-disabled = "rgba(240,224,216,0.58)"
 --error = "#FF5252"
 --on-error = "#000000"
 --success = "#81C784"