fix(worldclock): keep the local row's day label and legacy city names

The local row prepends "Local time" to the offset and day, so on a
phone a one-line summary cut off the day ("Tomorrow"), the part that
matters most on a long trip. It now wraps to two lines. Only Etc/
offsets and bare abbreviations are named by their offset; a legacy
place id such as US/Pacific keeps its place name. The picker's home
selection now derives from the same settings subscription the tab
uses.

app/src/main/java/de/jeanlucmakiola/clockula/domain/worldclock/ZoneCatalog.kt

@@ -69,11 +69,14 @@ object ZoneCatalog {
         entries.sortedWith(compareBy({ ZoneSearch.fold(it.city) }, { it.zoneId }))
 
     /**
-     * True for an id named after a place (`Asia/Tokyo`) or for [UTC]; false for
-     * the offset and abbreviation ids tzdata also lists (`Etc/GMT-9`, `CET`),
-     * whose last segment is no city and, for `Etc/GMT±n`, has the sign reversed.
+     * True when [cityFallbackFor] gives a fair name for [zoneId]: a place id,
+     * current (`Asia/Tokyo`) or legacy (`US/Pacific`), or [UTC]. False for the
+     * `Etc/` offsets and the bare abbreviations tzdata also lists (`Etc/GMT-9`,
+     * `CET`), whose last segment is no place and, for `Etc/GMT±n`, has the sign
+     * reversed.
      */
-    fun isCityId(zoneId: String): Boolean = zoneId == UTC || isRegionId(zoneId)
+    fun hasPlaceName(zoneId: String): Boolean =
+        zoneId == UTC || ('/' in zoneId && !zoneId.startsWith("Etc/"))
 
     private fun isRegionId(zoneId: String): Boolean =
         zoneId.contains('/') && zoneId.substringBefore('/') in REGIONS

app/src/main/java/de/jeanlucmakiola/clockula/ui/worldclock/WorldClockRow.kt

@@ -175,7 +175,9 @@ internal fun LocalClockRow(
                 tint = MaterialTheme.colorScheme.primary,
                 modifier = Modifier.size(24.dp),
             )
-            RowText(name = row.name, summary = summary, time = time)
+            // Two lines, not one: "Local time · " is prepended, and on a phone
+            // the day ("Tomorrow") is what an ellipsis would otherwise eat.
+            RowText(name = row.name, summary = summary, time = time, summaryMaxLines = 2)
         }
     }
 }
@@ -187,6 +189,7 @@ private fun RowScope.RowText(
     summary: String,
     time: String?,
     timeColor: Color = MaterialTheme.colorScheme.onSurface,
+    summaryMaxLines: Int = 1,
 ) {
     Column(modifier = Modifier.weight(1f)) {
         Text(
@@ -200,7 +203,7 @@ private fun RowScope.RowText(
             text = summary,
             style = MaterialTheme.typography.bodySmall,
             color = MaterialTheme.colorScheme.onSurfaceVariant,
-            maxLines = 1,
+            maxLines = summaryMaxLines,
             overflow = TextOverflow.Ellipsis,
         )
     }

app/src/main/java/de/jeanlucmakiola/clockula/ui/worldclock/WorldClockRowState.kt

@@ -113,7 +113,7 @@ internal object WorldClockRows {
         entries: Map<String, ZoneEntry>,
         zoneNames: Map<String, String?>,
     ): WorldClockRowState {
-        val name = if (ZoneCatalog.isCityId(deviceZone.id)) {
+        val name = if (ZoneCatalog.hasPlaceName(deviceZone.id)) {
             null
         } else {
             ZoneOffsetFormat.gmtLabel(ZoneComparisons.utcOffsetMinutes(deviceZone, now))

app/src/main/java/de/jeanlucmakiola/clockula/ui/worldclock/WorldClockSource.kt

@@ -35,13 +35,13 @@ internal class WorldClockSource @Inject constructor(
     /** What the picker needs before it can draw a row; null while it is still being built. */
     private data class Catalog(val entries: List<ZoneEntry>, val deviceCity: String)
 
-    private val storedHomeZoneId: Flow<String?> =
-        settings.defaults.map { it.homeZoneId }.distinctUntilChanged()
-
-    /** The two settings the tab reads, from one subscription to the defaults. */
+    /** The two settings the tab reads: the stored home zone and the local-clock switch. */
     private val tabSettings: Flow<Pair<String?, Boolean>> =
         settings.defaults.map { it.homeZoneId to it.automaticLocalClock }.distinctUntilChanged()
 
+    private val storedHomeZoneId: Flow<String?> =
+        tabSettings.map { it.first }.distinctUntilChanged()
+
     /**
      * The tab's state. Both the instant and the device zone are re-read on
      * **every tick**, which is what makes `TIME_SET` and `TIMEZONE_CHANGED`

app/src/test/java/de/jeanlucmakiola/clockula/domain/worldclock/LocalClockTest.kt

@@ -48,9 +48,8 @@ class LocalClockTest {
     }
 
     @Test
-    fun `the offset is the one at the instant, so DST counts`() {
-        // London is an hour behind Berlin all year, but Lisbon and London agree
-        // in summer and in winter: the rule is the offset now, not the zone id.
+    fun `the offset decides, not the zone id`() {
+        // Lisbon and London are different ids on the same offset; Berlin is not.
         assertThat(show(storedHome = "Europe/Lisbon", device = london)).isNull()
         assertThat(show(storedHome = "Europe/Berlin", device = london)).isEqualTo(london)
     }

app/src/test/java/de/jeanlucmakiola/clockula/domain/worldclock/ZoneCatalogTest.kt

@@ -226,10 +226,11 @@ class ZoneCatalogTest {
     }
 
     @Test
-    fun `a city id is a region id or UTC, never an offset or abbreviation`() {
-        assertThat(ZoneCatalog.isCityId("Asia/Tokyo")).isTrue()
-        assertThat(ZoneCatalog.isCityId("UTC")).isTrue()
-        assertThat(ZoneCatalog.isCityId("Etc/GMT-9")).isFalse()
-        assertThat(ZoneCatalog.isCityId("CET")).isFalse()
+    fun `a place id or UTC has a place name, an offset or abbreviation does not`() {
+        assertThat(ZoneCatalog.hasPlaceName("Asia/Tokyo")).isTrue()
+        assertThat(ZoneCatalog.hasPlaceName("US/Pacific")).isTrue()
+        assertThat(ZoneCatalog.hasPlaceName("UTC")).isTrue()
+        assertThat(ZoneCatalog.hasPlaceName("Etc/GMT-9")).isFalse()
+        assertThat(ZoneCatalog.hasPlaceName("CET")).isFalse()
     }
 }

docs/ARCHITECTURE.md

@@ -2407,7 +2407,7 @@ differ from it, so with no stored home the rule is always null, and Settings ›
 Clock says so under the switch rather than hiding it. A device set by UTC
 offset rather than by city reports an id like `Etc/GMT-9`, whose last segment
 has its sign reversed, so that row is named by its real offset ("GMT+9")
-instead (`ZoneCatalog.isCityId`).
+instead (`ZoneCatalog.hasPlaceName`).
 
 The row is not stored. It is `WorldClockUiState.Loaded.local`, built per tick
 by the source from the same `zones.current()` read the face uses, so a