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/measure/VoidingRecord.kt

@@ -4,6 +4,9 @@ import android.content.Context
 import android.content.SharedPreferences
 import com.google.gson.Gson
 import com.google.gson.reflect.TypeToken
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.launch
 import java.text.SimpleDateFormat
 import java.util.*
 
@@ -17,11 +20,16 @@ data class VoidingRecord(
     val method: String = "manual", // "manual", "voice", "camera"
     val timestamp: Long = System.currentTimeMillis()
 ) {
+    companion object {
+        private val timeFormat = SimpleDateFormat("HH:mm", Locale.getDefault())
+        private val dateFormat = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault())
+    }
+
     val timeString: String
-        get() = SimpleDateFormat("HH:mm", Locale.getDefault()).format(Date(timestamp))
+        get() = timeFormat.format(Date(timestamp))
 
     val dateString: String
-        get() = SimpleDateFormat("yyyy-MM-dd", Locale.getDefault()).format(Date(timestamp))
+        get() = dateFormat.format(Date(timestamp))
 
     val displayText: String
         get() = when {
@@ -35,6 +43,7 @@ data class VoidingRecord(
 /**
  * 로컬 배뇨 기록 저장소 (SharedPreferences + JSON)
  */
+@OptIn(kotlinx.coroutines.DelicateCoroutinesApi::class)
 object VoidingRecordStore {
     private const val PREFS_NAME = "voiding_records"
     private const val KEY_RECORDS = "records"
@@ -61,11 +70,15 @@ object VoidingRecordStore {
     }
 
     fun clear(context: Context) {
-        prefs(context).edit().remove(KEY_RECORDS).apply()
+        GlobalScope.launch(Dispatchers.IO) {
+            prefs(context).edit().remove(KEY_RECORDS).apply()
+        }
     }
 
     private fun save(context: Context, records: List<VoidingRecord>) {
-        prefs(context).edit().putString(KEY_RECORDS, gson.toJson(records)).apply()
+        GlobalScope.launch(Dispatchers.IO) {
+            prefs(context).edit().putString(KEY_RECORDS, gson.toJson(records)).apply()
+        }
     }
 
     fun getToday(context: Context): List<VoidingRecord> {