feat(contacts): switchable Cards / List / Table view for the address list

Add a persisted view toggle so the contacts address list can be rendered three
ways, moving it away from a bare data-grid toward a Material look:

- Cards: tactile rounded cards with a circular Z/T type-avatar, label over a muted
  truncated address, trailing globe badge, primary-tint + outline selection, hover
  fill, and a centred Material empty state.
- List: borderless two-line rows (same avatar + label/address) with hover tint and a
  thin per-row divider — denser than cards.
- Table: the previous 3-column table, material-ized (grid borders dropped, row
  backgrounds + interactive sort kept).

The toggle is an icon SegmentedControl (view-agenda / view-list / table-rows)
right-aligned on the toolbar; the choice persists via a new contacts_view_mode_
setting (0 cards / 1 list / 2 table, mirroring portfolio_style_). Cards/List sort by
label; Table keeps its sortable headers. All geometry is dpiScale()-aware; the globe
badge is drawn in the icon font in every mode. Default is Cards.

Build + ctest + hygiene clean.

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

src/config/settings.h

@@ -184,6 +184,9 @@ public:
     // Left/Right arrows on the Market tab (like the Overview layouts).
     int getPortfolioStyle() const { return portfolio_style_; }
     void setPortfolioStyle(int v) { portfolio_style_ = (v < 0 || v > 2) ? 0 : v; }
+    // Contacts tab address-list view: 0 = cards, 1 = list, 2 = table.
+    int getContactsViewMode() const { return contacts_view_mode_; }
+    void setContactsViewMode(int v) { contacts_view_mode_ = (v < 0 || v > 2) ? 0 : v; }
 
     // Console scanline effect
     bool getScanlineEnabled() const { return scanline_enabled_; }
@@ -490,6 +493,7 @@ private:
 #endif
     std::string balance_layout_ = "classic";
     int portfolio_style_ = 0;   // Market portfolio row style (0 single / 1 two-line / 2 hero)
+    int contacts_view_mode_ = 0;   // Contacts address-list view (0 cards / 1 list / 2 table)
     bool scanline_enabled_ = true;
     bool console_line_accents_ = true;   // left color accent bars in console output
     bool console_text_color_ = true;     // per-channel text coloring in console output