Grey out what Home Assistant calls off and colour the rest like Home Assistant, so an airco that is off no longer looks on (0.2.85)

The airco tile stayed orange while the airco was off. The firmware kept its own
short list of what turns grey and gave an off climate Home Assistant's orange,
but Home Assistant has no colour for a climate that is off: its cards fall back
to the inactive grey. Other tiles had the same fault: an off fan, a closed
blind, a docked robot, a player in standby, an idle script, a paused timer and
a camera that isn't streaming all kept their colour.

Tile::active() is now a port of the frontend's stateActive() for the domains a
tile can show, and every tile that is not active is grey. An airco that is off
reads Off, with the room's temperature when the device reports one, as Home
Assistant's tile does. tile_controls::accent() follows stateColorCss(): alarm
binary sensors red, a battery green, orange or red by its charge, a running
script or timer and a streaming camera amber, the weather per condition, the
sun amber and indigo, someone in a zone blue. Scenes, selects, numbers and
sensors keep their own colour per kind. A full-page tile lights up only for
tiles that can be off (Tile::lights_up), and a closed blind's slider keeps its
colour. The top bar's alarm classes are Home Assistant's eleven.

Checked with tools/check.sh (471 Python tests, 19/19 C++ with 58 state cases
and every colour rule) and compiled for both boards: CYD 1,677,488 B (91.4 %,
+576 B), Guition 2,054,640 B (25.3 %).

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

README_EXTENDED.md

@@ -52,6 +52,9 @@ on the screen itself, and how updates work.
   drag them straight into the screen mockup; **Double-width** is an option for every tile, and so is
   **Full page** (firmware 0.2.62+): the tile takes the whole page and is one big button that lights up
   in its state colour while on, so a screen by the door switches the light when you push anywhere on it.
+  Only something that can be off lights up: a light, switch, airco, fan, blind, speaker, robot, script,
+  timer, camera, person or binary sensor. Sensors, numbers, selects, scenes, the weather and the sun stay plain
+  (firmware 0.2.71+).
   Its small slider, direct controls or graph sit at the bottom of the page. A **Go to page** tile
   (`screen.page_1` to `screen.page_8`) opens another page: a full-page light switch on page 1, a menu on page 2.
   Under **Goes to page** the editor offers the pages the screen has and the next, empty one, where a new sub-page
@@ -83,7 +86,13 @@ on the screen itself, and how updates work.
 - **Home Assistant's words and icons** (app 0.2.67 / firmware 0.2.58): a blind says Open or
   Closing, a speaker Playing and a door Open or Closed, a sensor shows the decimals Home Assistant
   shows, and a tile without an icon of its own gets the one Home Assistant shows, following its
-  state. A light or binary sensor that is off turns grey (firmware 0.2.53+).
+  state.
+- **Home Assistant's colours** (firmware 0.2.71+): a tile turns grey whenever Home Assistant calls
+  its entity inactive, by the same rule its own cards use: a light, switch or fan that is off, an
+  airco that is off (its tile then says Off), a closed blind, a docked robot, a player in standby,
+  a paused timer. Otherwise it takes Home Assistant's colour for the state: an airco per mode, an
+  alarm sensor red, a battery green, orange or red by its charge, the weather by its condition.
+  Scenes, selects, numbers and sensors keep a colour of their own per kind.
 - **Weather card** with current weather, the coming hours and days including chance of
   rain or millimeters; **climate card** with an on/off button, mode, fan, and swing settings.
   The target temperature sits big between − / + keys with one row of mode keys below; the