feat(market): 3-cell min groups, full accent outline, tighter chart, no scrollbar

- Portfolio groups now default to the 3-cell minimum height (was 4). The card
  design adapts: below ~112px it drops the redundant DRGX footer and uses the
  compact hero font so a 3-cell card stays legible.
- Group accent color is now a colored outline around the whole card (and the
  editor's live preview) instead of a stripe on the left edge; the text no longer
  reserves the old left-stripe offset.
- Price chart: trim the empty band between the 24H VOLUME stats and the chart
  (smaller hero-header bottom pad), and keep the Y-axis price labels inside the
  card on narrow windows (clamp to the card's left edge + bump min y-axis padding
  40->54) so they no longer spill onto the tab background.
- Market tab no longer draws a scrollbar (NoScrollbar); the portfolio grid still
  scrolls via the mouse wheel.

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

res/themes/ui.toml

@@ -874,7 +874,7 @@ accent-stripe-inset-ratio = { size = 0.0 }
 accent-stripe-left-offset = { size = 0.0 }
 accent-stripe-width = { size = 4.0 }
 accent-stripe-rounding = { size = 1.5 }
-chart-y-axis-min-padding = { size = 40.0 }
+chart-y-axis-min-padding = { size = 54.0 }
 chart-y-axis-padding = { size = 70.0 }
 chart-dot-min-radius = { size = 1.5 }
 chart-dot-radius = { size = 2.0 }