refactor(companion): extract drawRowSelection() for the canonical list-row bar

Every drawList/AccordionList row opened with the same hand-written
display.drawSelectionRow(0, y-1, width-reserve, lineStep-1, sel) line —
14 copies of the same geometry and magic offsets. Add a drawRowSelection(d,
y, sel, reserve) helper in icons.h next to drawList and route the canonical
sites through it (Bot/LiveShare/Locator/Repeater/Settings/Tools/Nearby/
QuickMsg/Waypoints).

Rows that intentionally differ (full-width DashboardConfig/QuickMsg, the
keyboard/ringtone grids) keep their explicit drawSelectionRow() call — the
helper is opt-in rather than baked into drawList, so legitimate variants
aren't forced into one geometry. Framework doc updated to match.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

examples/companion_radio/ui-new/ToolsScreen.h

@@ -75,7 +75,7 @@ public:
     _acc.render(display,
       // Section header: "[+/-] <icon> Name"
       [&](int sec, int y, bool sel, int reserve, bool collapsed) {
-        display.drawSelectionRow(0, y - 1, display.width() - reserve, display.lineStep() - 1, sel);
+        drawRowSelection(display, y, sel, reserve);
         display.setCursor(2, y);
         display.print(collapsed ? "+" : "-");
         const int icon_x = 2 + cw + 2;
@@ -85,7 +85,7 @@ public:
       },
       // Item: indented "<icon> Label"
       [&](int sec, int item, int y, bool sel, int reserve) {
-        display.drawSelectionRow(0, y - 1, display.width() - reserve, display.lineStep() - 1, sel);
+        drawRowSelection(display, y, sel, reserve);
         const int icon_x = 2 + cw + 2;   // align item icons under the header icon
         // drawIcon(display, icon_x, y, SECTIONS[sec].tools[item].icon); // icons disabled for now, don't fit visually
         display.setCursor(icon_x + g, y);