fix(alarm): point the next-alarm show intent at the app, not the ring screen

The `AlarmClockInfo` show intent — what the status-bar alarm icon and the
lockscreen's next-alarm line open — targeted `AlarmRingActivity` with
`CLEAR_TASK`. Tapping it opened a ring screen for an alarm that was not
ringing, which resolved to "finished" and closed itself again.

It now opens the app on its Alarms tab. That show intent is what "next-alarm
publishing" means, so the rule pinning it belongs to this milestone.

app/src/main/java/de/jeanlucmakiola/clockula/alarm/android/AndroidAlarmScheduler.kt

@@ -5,13 +5,13 @@ import android.app.PendingIntent
 import android.content.Context
 import android.content.Intent
 import dagger.hilt.android.qualifiers.ApplicationContext
+import de.jeanlucmakiola.clockula.MainActivity
 import de.jeanlucmakiola.clockula.alarm.AlarmCapabilities
 import de.jeanlucmakiola.clockula.alarm.AlarmIntents
 import de.jeanlucmakiola.clockula.alarm.AlarmScheduler
 import de.jeanlucmakiola.clockula.alarm.receiver.AlarmFireReceiver
 import de.jeanlucmakiola.clockula.domain.alarm.ScheduleMode
 import de.jeanlucmakiola.clockula.domain.alarm.SchedulingPolicy
-import de.jeanlucmakiola.clockula.ui.ring.AlarmRingActivity
 import kotlin.time.Instant
 import javax.inject.Inject
 import javax.inject.Singleton
@@ -92,12 +92,20 @@ class AndroidAlarmScheduler @Inject constructor(
         PENDING_INTENT_FLAGS,
     )
 
-    /** What the system opens when the user taps the status-bar alarm icon. */
+    /**
+     * What the system opens when the user taps the status-bar alarm icon or the
+     * lockscreen's next-alarm line: the **alarms list**, which is what "show me
+     * my next alarm" means. It pointed at the ring screen until M9, so tapping
+     * it opened a ring screen for an alarm that was not ringing, which resolved
+     * to `Finished` and closed itself (M9 D21). `MainActivity` is `singleTop`,
+     * so an existing task is brought forward and `onNewIntent` selects the tab.
+     */
     private fun showPendingIntent(): PendingIntent = PendingIntent.getActivity(
         context,
         AlarmIntents.REQUEST_SHOW,
-        Intent(context, AlarmRingActivity::class.java).apply {
+        Intent(context, MainActivity::class.java).apply {
-            flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
+            action = AlarmIntents.ACTION_SHOW_ALARMS
+            flags = Intent.FLAG_ACTIVITY_NEW_TASK
         },
         PENDING_INTENT_FLAGS,
     )