feat: consent screen, reminder system, medical metrics, sex field, design tokens, code quality

A. Reminder: ReminderService (AlarmManager chain), ReminderSettingsView,
   bell icon in Piezo top bar, reschedule on catheterization
B. Consent: ConsentView (3 mandatory items), onboarding→consent→registration flow,
   persistent consent storage, sex field in User + Registration Step 2
C. Diary: 24hUV, NUV, NPI, max capacity, day/night frequency metrics card
D. Design: DesignTokens.kt, 48dp touch targets, DonutChart semantics, pressScale modifier
E. Quality: BuildConfig.DEBUG log wrapping, DateFormatter caching, background I/O for diary store

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/src/main/java/com/example/medilightv2android/MainActivity.kt

@@ -30,6 +30,8 @@ import com.example.medilightv2android.ui.views.personalization.PiezoPersonalizat
 import com.example.medilightv2android.ui.views.pin.PinMode
 import com.example.medilightv2android.ui.views.pin.PinView
 import com.example.medilightv2android.ui.views.registration.RegistrationView
+import com.example.medilightv2android.ui.views.consent.ConsentView
+import com.example.medilightv2android.ui.views.reminder.ReminderSettingsView
 import com.example.medilightv2android.ui.views.sensorselect.SensorSelectView
 
 class MainActivity : ComponentActivity() {
@@ -65,6 +67,7 @@ fun MedilightApp(modifier: Modifier = Modifier) {
     ) { screen ->
         when (screen) {
             AppScreen.ONBOARDING -> OnboardingView(appState)
+            AppScreen.CONSENT -> ConsentView(appState)
             AppScreen.REGISTRATION -> RegistrationView(appState)
             AppScreen.HOME -> HomeView(appState)
             AppScreen.SENSOR_SELECT -> SensorSelectView(appState)
@@ -84,6 +87,9 @@ fun MedilightApp(modifier: Modifier = Modifier) {
                 },
                 onCancel = { appState.currentScreen = AppScreen.PIEZO_MONITORING }
             )
+            AppScreen.REMINDER_SETTINGS -> ReminderSettingsView(
+                onBack = { appState.backToMonitoring() }
+            )
         }
     }
 }