Notation like Home Assistant, each screen in its own language, and the language in every build

From the end-to-end test on the bench boards and an independent review:
- Units spaced as Home Assistant does (54% / 54 % in German and French, 18°, 21.5 °C), in the firmware and the app.
- Grouping from five digits where the language does (1234 but 12.345 in Spanish, Polish, Portuguese): the layout
  message carries group_min and percent_space; an unknown number style no longer refuses a layout.
- Automatic follows Home Assistant's own language for the clock and numbers, also without a translation (Swedish:
  24 hours, 1 234,5; pt-BR: 1.234,5): regions.json from the CLDR for all 63 languages Home Assistant offers.
- 12-hour clock: the top bar says 3:48 PM, the clock card 3:48 (not 03:48), Last runs follow the clock.
- The climate setpoint font has the decimal comma; the value fonts have ², ³ and µ (m³ was a box).
- Weather days: at most three letters without the dot (mié, sáb, czw); the screen took three bytes.
- Texts fall back per key through the base language (pt-BR -> pt -> en) in the firmware and the app.
- Each screen gets the app's words in the language its firmware speaks; firmware from before the languages gets
  English and its own letters, not boxes.
- set_language re-reads what it writes (indentation, comments, quoted keys, CRLF, !include) and every build writes
  the language first; the 24-hour pin no longer hits a fresh install and waits for the old clock switches.
- Tests: region and notation, plural parity with the C++ rules, set_language edge cases, the pin, PUT /api/language.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

components/smart_display/settings_screen.h

@@ -190,21 +190,17 @@ inline std::string duration_text(int32_t seconds) {
 }
 // Minutes since midnight as the clock on this screen shows them.
 inline std::string moment_text(int32_t minutes, bool clock_24h) {
-  char buffer[16];
-  int hour = minutes / 60, minute = minutes % 60;
-  if (clock_24h) snprintf(buffer, sizeof(buffer), "%02d:%02d", hour, minute);
-  else snprintf(buffer, sizeof(buffer), "%d:%02d %s", hour % 12 ? hour % 12 : 12, minute,
-                screen_text::tr(hour < 12 ? screen_text::txt::time_am : screen_text::txt::time_pm));
-  return buffer;
+  char buffer[8];
+  snprintf(buffer, sizeof(buffer), "%02d:%02d", (int) (minutes / 60 % 24), (int) (minutes % 60));
+  return screen_text::clock_text(buffer, clock_24h);
 }
 // What the right-hand side of a row says. A toggle draws a switch instead, its text is for the tests.
 inline std::string value_text(const Row &row) {
   switch (row.kind) {
     case Kind::toggle: return screen_text::tr(row.read && row.read() ? screen_text::txt::ha_on : screen_text::txt::ha_off);
     case Kind::number: {
-      char buffer[24];
-      snprintf(buffer, sizeof(buffer), "%d%s", row.read ? (int) row.read() : 0, row.unit);
-      return buffer;
+      int value = row.read ? (int) row.read() : 0;
+      return strcmp(row.unit, "%") == 0 ? screen_text::percent(value) : std::to_string(value) + row.unit;
     }
     case Kind::duration: return duration_text(row.read ? row.read() : 0);
     case Kind::moment: return moment_text(row.read ? row.read() : 0, screen_settings::current.clock_24h != 0);