release: cut 2.16.0

Locale-aware calendar titles (#60): Month, Week and Day move onto the shared
formatter Agenda already used, the year drops out while you're in the current
one, and the Week title names its month rather than restating the day numbers
printed directly below it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

fastlane/metadata/android/en-US/changelogs/21600.txt

@@ -0,0 +1,18 @@
+### Changed
+- Dates in the Month, Week and Day title bars now follow your language and
+  region instead of one hardcoded layout. Every date was rendered in a fixed
+  German-style order with a trailing dot on the day number, whatever your
+  settings: US English showed "Fri, 17. Jul 2026" where it should read
+  "Fri, Jul 17". The Agenda view already formatted correctly, so the two
+  disagreed about the same date. All four views now share one formatter, and the
+  day/month order, the separators and the ordinal all come from your locale —
+  so English-in-Germany reads "Fri, 17 Jul" and English-in-the-US "Fri, Jul 17",
+  each correct for where you are ([#60]).
+- The title bar drops the year while you're in the current one — "July" rather
+  than "July 2026". The year reappears the moment you page out of the current
+  year, which is when it tells you something you didn't already know.
+- The Week view's title now names the month instead of spelling out the day range.
+  "24. Jun – 31. Jun" restated the day numbers already printed in the column
+  headers right below it, in the widest string in the bar. A week that straddles
+  two months keeps the outgoing month until it is fully gone ([#60]).
+