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>

screen_manager/app/updates.py

@@ -103,9 +103,19 @@ class Updater:
 
     def language_due(self, screen):
         """True when a screen speaks another language than Settings -> Language & region says (app 0.2.90): its
-        "Screen language" sensor, or English for firmware from before that sensor."""
+        "Screen language" sensor, or English for firmware from before that sensor. A sensor without a state yet (the
+        screen restarts) says nothing."""
         region = getattr(self.manager, 'region', None)
-        return bool(region) and (screen.get('language') or 'en') != region.language()
+        if not region or (screen.get('language_sensor') and not screen.get('language')):
+            return False
+        return (screen.get('language') or 'en') != region.language()
+
+    def speaks_region(self, screen):
+        """Whether the screen says it speaks the language of Settings -> Language & region: what an update waits for."""
+        region = getattr(self.manager, 'region', None)
+        if not region:
+            return True
+        return (screen.get('language') if screen.get('language_sensor') else 'en') == region.language()
 
     def state_for(self, screen, profiles=None):
         version = parse_version(screen.get('firmware'))
@@ -251,7 +261,7 @@ class Updater:
         while time.monotonic() < deadline:
             screen = self.screen(inbox)
             version = parse_version(screen.get('firmware')) if screen else None
-            if screen and screen['online'] and version and version >= TARGET and not self.language_due(screen):
+            if screen and screen['online'] and version and version >= TARGET and self.speaks_region(screen):
                 return True
             await asyncio.sleep(self.poll_seconds)
         return False