refactor(ui): move the alarm time formatter where both screens can reach it

The ring screen wrote it first; the alarms list needs the same 12/24-hour
rendering. Moved rather than copied.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Wmy1BpCKi8KeSjaWhYuCPV

app/src/main/java/de/jeanlucmakiola/clockula/ui/common/AlarmTimeFormatter.kt

@@ -1,4 +1,4 @@
-package de.jeanlucmakiola.clockula.ui.ring
+package de.jeanlucmakiola.clockula.ui.common
 
 import android.text.format.DateFormat
 import androidx.compose.runtime.Composable
@@ -10,7 +10,11 @@ import java.time.LocalTime
 import java.time.format.DateTimeFormatter
 import java.time.format.FormatStyle
 
-/** Honours the user's 12/24-hour setting. Deliberately not unit-tested: it is one platform call. */
+/**
+ * Honours the user's 12/24-hour setting. Deliberately not unit-tested: it is
+ * one platform call. Shared by the ring screen, the alarm list and the editor,
+ * so all three read a time the same way (M5).
+ */
 @Composable
 internal fun rememberAlarmTimeFormatter(): (TimeOfDay) -> String {
     val context = LocalContext.current

app/src/main/java/de/jeanlucmakiola/clockula/ui/ring/RingScreen.kt

@@ -33,6 +33,7 @@ import androidx.compose.ui.draw.scale
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import de.jeanlucmakiola.clockula.R
+import de.jeanlucmakiola.clockula.ui.common.rememberAlarmTimeFormatter
 import de.jeanlucmakiola.floret.identity.collapseExit
 import de.jeanlucmakiola.floret.identity.expandEnter
 import de.jeanlucmakiola.floret.identity.rememberReduceMotion