UI-05: rebuild Record screen as the Map HUD (design north star)

Replaces the scrolling stats-card layout with the full-bleed Map HUD:
UI-04's draggable/resizable HUD widgets float over UI-01's shared
background map (full opacity on this tab), and the old Pause/Stop/Resume/
Discard buttons become full-bleed, icon-only segments matching the
mockup's tertiary-container/error-container colors exactly. The idle
state keeps its prior compact layout deliberately -- HUD widgets only
appear once a ride exists, preserving the existing "a resting screen
must not look like a ride going nowhere" guarantee rather than
reinterpreting it.

State-machine logic (ticker, wakelock, speed subscription, error
handling) is untouched; every pre-existing record-screen test passed
unchanged against the rebuilt screen. Added tests that actually tap
Start/Pause/Stop and verify engine state changes, confirm HUD widgets
render over the map rather than replacing it, and verify the
mounted-mode speed digit's real contrast ratio against GlassPanel's
translucent surface specifically (the ticket's own named risk).

Corrects a UI-04 mistake found while implementing this ticket: the HUD's
default four metrics were ordered Speed/Distance/Elapsed/Max Speed, a
guess made before reading the actual Map HUD mockup HTML closely. The
real fixed row is Speed/Avg Speed/Dist/Time -- reordered HudMetric to
match and updated every test that asserted the old order.

Adds PulsingLocationMarker (UI-03) to RideMap's live usage via a new
showLocationMarker flag, and explicit tertiaryContainer/errorContainer
tokens to ripprColors so the control bar matches the design system's
literal values rather than an auto-derived tonal palette.

Verified end-to-end on a real emulator: Start, Pause, Resume, and Stop
all correctly drive the trip state machine with the full live map behind
everything. A lengthy false alarm during this verification (taps
appearing to do nothing) turned out to be a screenshot-scale
mis-measurement on the verification side, not an app defect -- resolved
by sampling pixel colors directly from the raw screenshot to find the
control bar's true on-screen position.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012Xki7YAcc2TiN2PRZJ2tXr

test/hud_edit_overlay_test.dart

@@ -108,6 +108,6 @@ void main() {
     await tester.pumpAndSettle();
 
     expect(find.text('Speed'), findsOneWidget, reason: 'visible by default');
-    expect(find.text('Average speed'), findsNothing, reason: 'hidden by default');
+    expect(find.text('Max speed'), findsNothing, reason: 'hidden by default');
   });
 }