V3-05: mounted (handlebar) mode

Wake lock via a WakelockController seam (mirrors LocationSource), gated strictly to actual recording and released on stop/discard/navigate-away/dispose. High-contrast ripprMountedTheme() applied only to the record screen. BigStat gained a scale param for the headline figure rather than a blanket TextTheme.apply, which crashes on Material 3's default theme.

lib/src/ui/components/stats.dart

@@ -17,12 +17,18 @@ class BigStat extends StatelessWidget {
     required this.label,
     required this.value,
     required this.unit,
+    this.scale = 1.0,
   });
 
   final String label;
   final String value;
   final String unit;
 
+  /// V3-05: mounted mode reads bigger, at a glance, at speed. Fixed pixel sizes below
+  /// (not the ambient text theme) are what a glove-and-visor readout actually is, so
+  /// scaling has to happen here rather than through `Theme.of(context).textTheme`.
+  final double scale;
+
   @override
   Widget build(BuildContext context) {
     final colors = Theme.of(context).colorScheme;
@@ -33,7 +39,7 @@ class BigStat extends StatelessWidget {
         Text(
           label,
           style: TextStyle(
-            fontSize: 13,
+            fontSize: 13 * scale,
             letterSpacing: 2,
             color: colors.outline,
           ),
@@ -46,7 +52,7 @@ class BigStat extends StatelessWidget {
             Text(
               value,
               style: monoDigits.copyWith(
-                fontSize: 64,
+                fontSize: 64 * scale,
                 fontWeight: FontWeight.bold,
                 // Named explicitly. The Compose version rendered black-on-black when the
                 // ambient content colour went missing.
@@ -55,7 +61,7 @@ class BigStat extends StatelessWidget {
             ),
             Text(
               ' $unit',
-              style: TextStyle(fontSize: 18, color: colors.outline),
+              style: TextStyle(fontSize: 18 * scale, color: colors.outline),
             ),
           ],
         ),