[android] Add OpenStateTextFormatter and JVM tests

- Introduce a tiny, pure formatter for opening-hours labels:
	- `formatHoursMinutes(12/24h)`, `isSameLocalDate()`, `dayShort()`
	- `buildAtLabel(...)` that accepts already-localized templates
- Add JVM unit tests for hour formatting and label selection.

Signed-off-by: NoelClick <dev@noel.click>
(cherry picked from commit df4b5f2281607e5a35b98b1007fb34eabd4aa657)
Signed-off-by: NoelClick <dev@noel.click>

android/app/src/main/java/app/organicmaps/widget/placepage/OpenStateTextFormatter.java

@@ -0,0 +1,49 @@
+package app.organicmaps.widget.placepage;
+
+import java.time.ZonedDateTime;
+import java.time.format.TextStyle;
+import java.util.Locale;
+
+public class OpenStateTextFormatter
+{
+  private OpenStateTextFormatter() {}
+
+  static String formatHoursMinutes(int hour, int minute, boolean use24h)
+  {
+    if (use24h)
+      return String.format(Locale.ROOT, "%02d:%02d", hour, minute);
+
+    int h = hour % 12;
+    if (h == 0) h = 12;
+    String ampm = (hour < 12) ? "AM" : "PM";
+    return String.format(Locale.ROOT, "%d:%02d %s", h, minute, ampm);
+  }
+
+  static boolean isSameLocalDate(ZonedDateTime a, ZonedDateTime b)
+  {
+    return a.toLocalDate().isEqual(b.toLocalDate());
+  }
+
+  static String dayShort(ZonedDateTime t, Locale locale)
+  {
+    return t.getDayOfWeek().getDisplayName(TextStyle.SHORT, locale);
+  }
+
+  static String buildAtLabel(
+      boolean opens,
+      boolean isToday,
+      String dayShort,
+      String time,
+      String opensAtLocalized,
+      String closesAtLocalized,
+      String opensDayAtLocalized,
+      String closesDayAtLocalized
+  )
+  {
+    if (isToday)
+      return opens ? String.format(Locale.ROOT, opensAtLocalized, time) // Opens at %s
+          : String.format(Locale.ROOT, closesAtLocalized, time); // Closes at %s
+    return opens ? String.format(Locale.ROOT, opensDayAtLocalized, dayShort, time) // Opens %s at %s
+        : String.format(Locale.ROOT, closesDayAtLocalized, dayShort, time); // Closes %s at %s
+  }
+}

android/app/src/test/java/app/organicmaps/widget/placepage/OpenStateTextFormatterTest.java

@@ -0,0 +1,72 @@
+package app.organicmaps.widget.placepage;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.util.Locale;
+
+public class OpenStateTextFormatterTest
+{
+  private static final String OPENS_AT = "Opens at %s";
+  private static final String CLOSES_AT = "Closes at %s";
+  private static final String OPENS_DAY_AT = "Opens %1$s at %2$s";
+  private static final String CLOSES_DAY_AT = "Closes %1$s at %2$s";
+
+  @Test
+  public void formatHoursMinutes_24h()
+  {
+    assertEquals("09:00", OpenStateTextFormatter.formatHoursMinutes(9, 0, true));
+    assertEquals("18:05", OpenStateTextFormatter.formatHoursMinutes(18, 5, true));
+  }
+
+  @Test
+  public void formatHoursMinutes_12h()
+  {
+    assertEquals("9:00 AM", OpenStateTextFormatter.formatHoursMinutes(9, 0, false));
+    assertEquals("6:05 PM", OpenStateTextFormatter.formatHoursMinutes(18, 5, false));
+    assertEquals("12:00 PM", OpenStateTextFormatter.formatHoursMinutes(12, 0, false));
+    assertEquals("12:00 AM", OpenStateTextFormatter.formatHoursMinutes(0, 0, false));
+  }
+
+  @Test
+  public void buildAtLabel_today_open_close()
+  {
+    String open = OpenStateTextFormatter.buildAtLabel(true, true, "Sat", "09:00",
+        OPENS_AT, CLOSES_AT, OPENS_DAY_AT, CLOSES_DAY_AT);
+    String close = OpenStateTextFormatter.buildAtLabel(false, true, "Sat", "18:00",
+        OPENS_AT, CLOSES_AT, OPENS_DAY_AT, CLOSES_DAY_AT);
+    assertEquals("Opens at 09:00", open);
+    assertEquals("Closes at 18:00", close);
+  }
+
+  @Test
+  public void buildAtLabel_other_day()
+  {
+    String open = OpenStateTextFormatter.buildAtLabel(true, false, "Sat", "09:00",
+        OPENS_AT, CLOSES_AT, OPENS_DAY_AT, CLOSES_DAY_AT);
+    String close = OpenStateTextFormatter.buildAtLabel(false, false, "Tue", "18:00",
+        OPENS_AT, CLOSES_AT, OPENS_DAY_AT, CLOSES_DAY_AT);
+    assertEquals("Opens Sat at 09:00", open);
+    assertEquals("Closes Tue at 18:00", close);
+  }
+
+  @Test
+  public void isSameLocalDate_and_dayShort_helpers()
+  {
+    ZonedDateTime a = ZonedDateTime.of(2025, 3, 1, 10, 0, 0, 0, ZoneId.of("Europe/Paris"));
+    ZonedDateTime b = ZonedDateTime.of(2025, 3, 1, 22, 0, 0, 0, ZoneId.of("Europe/Paris"));
+    ZonedDateTime c = a.plusDays(1);
+
+    assertTrue(OpenStateTextFormatter.isSameLocalDate(a, b));
+    assertFalse(OpenStateTextFormatter.isSameLocalDate(a, c));
+
+    String day = OpenStateTextFormatter.dayShort(c, Locale.US);
+    // March 2, 2025 is a Sunday; "Sun" in US locale
+    assertEquals("Sun", day);
+  }
+}