Unify header pill/button height to 38px, matching the HTML prototype

Measured the prototype screenshot pixel-for-pixel: content pills take
up ~79% of the header's total height, matching its own CSS
(height:38px, topBarWrap padding:5px 10px -> 48px total). The Flutter
port had drifted to 34px for HeaderWindPill, MapSearchControls, and
NavIconButton, while FlightModePill was left at the original 38px -
so Fly mode looked inconsistent against itself, and both modes wasted
more header height as margin than the prototype does. Bringing all
four back to a shared 38px fixes both.

app/lib/ui/widgets/header_wind_pill.dart

@@ -19,13 +19,17 @@ class HeaderWindPill extends ConsumerWidget {
     return GestureDetector(
       onTap: () => ref.read(headerWindProvider.notifier).toggleShowPerWaypoint(),
       child: Container(
-        height: 34,
+        // 38 statt vorher 34 (Nutzerwunsch: Kopfleisten-Pillen/-Buttons
+        // einheitlich auf die im HTML-Demonstrator vermessene Hoehe bringen,
+        // siehe TopModeBar-Klassendoku) - deckungsgleich mit FlightModePill,
+        // das schon immer 38 nutzte.
+        height: 38,
         padding: const EdgeInsets.symmetric(horizontal: 10),
         decoration: BoxDecoration(
           color: active
               ? const Color(0xFF4D9DFF).withValues(alpha: 0.32)
               : Colors.black.withValues(alpha: 0.55),
-          borderRadius: BorderRadius.circular(17),
+          borderRadius: BorderRadius.circular(19),
           border: Border.all(
             color: active
                 ? const Color(0xFF4D9DFF)