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/claude_skill.py

@@ -283,13 +283,14 @@ Every screen has these entities in Home Assistant, on its ESPHome device. `<scre
 | `switch.<screen>_dark_mode` | On: the dark look, a black page with graphite cards and soft white text, for a screen beside a bed or in a dark room. Off: the light look. Firmware {DARK_MODE_MIN_FIRMWARE} or newer. |
 | `switch.<screen>_night_mode` | Night mode: the night brightness between the two times below. Firmware {SETTING_ENTITIES_MIN_FIRMWARE} or newer, like every row below it. |
 | `time.<screen>_night_starts`, `time.<screen>_night_ends` | The night hours; set them with `time.set_value`. |
-| `switch.<screen>_24_hour_clock` | On: 24-hour clock. Off: 12-hour clock. |
 | `switch.<screen>_back_to_page_1` | On: after `number.<screen>_back_to_page_1_after` seconds without a touch (30 to 3600) the screen closes a card and goes back to page 1. Pressing Wake, an alert or Auto standby don't count as a touch. |
 | `switch.<screen>_back_to_page_1_on_standby` | On: going into standby also goes back to page 1. |
 | `switch.<screen>_swipe_between_pages` | On: swipe between pages. |
 | `switch.<screen>_page_buttons` | On: the Previous and Next bar under the tiles on a screen with more than one page. Off: no bar, the tiles take its room, and only swiping or Go to page tiles change the page. Firmware {PAGE_BUTTONS_MIN_FIRMWARE} or newer. |
 | `select.<screen>_rotation` | Guition only: `0°`, `90°`, `180°` or `270°`. |
 
+The 12 or 24-hour clock, the language and how numbers are written are one choice for every screen, in ESP Screens under Settings → Language & region; no entity changes them (firmware 0.2.76 or newer; older firmware still has `switch.<screen>_24_hour_clock`).
+
 Wake and Sleep are buttons: press them with the `button.press` action. They save nothing, so an automation may press them as often as it likes, on every motion too. To reach several screens at once, list their buttons under `entity_id`. Don't target an area or a device with `button.press`: that presses every other button there as well, the Wake and Sleep of the same screen included.
 
 ```yaml