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>

src/config/settings.h

@@ -96,7 +96,7 @@ public:
         int gridCol = -1;
         int gridRow = -1;
         int gridW = 6;
-        int gridH = 4;
+        int gridH = 3;                 // minimum group height (cells); card design adapts below ~4
     };
 
     // Theme