Add a card for blinds and curtains, and fix what Studio 1 showed after 0.2.57 (0.2.58)

A tap on a cover now opens a card like Home Assistant's own, in the style
of the climate and vacuum cards: a tall position slider on which the blind
hangs from the top, a tilt slider over slats for venetian blinds, and open,
stop and close keys. The key of the direction the cover moves is filled; a
key that cannot move it further is disabled and stays out of the keys the
card's tick enables. Sliders show their value while dragged and send it on
release. The card offers only what supported_features allows. A
battery-powered blind shows its battery at the top right: the app sends
the device's battery sensor as the extra the vacuum card uses, and adds
current_tilt_position to the attributes.

Checking Studio 1 after its update to firmware 0.2.49 found that a setting
number equal to its initial state 0 (night brightness 0 %) was never
published, so Home Assistant kept it unknown and ESP Screens could not
change it; apply_screen_settings now publishes a number without a state.
The app also took "unavailable" for the device name during the restart
and wrote sensor.esp_screens_unavailable; diagnostics ignore unknown and
unavailable. The editor redraws its tiles, top bar and entity list when
the live stream opened a screen before the first full inventory (a busy
add-on), and loads app.js and style.css by content stamp after Safari kept
an old script.

Checked with 254 Python and 14 C++ tests, generate_packages --check, ESP32
builds of both profiles, and 20 API checks of the card on host builds of
both boards. Firmware 0.2.50.

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

tests/test_tile_controls.cpp

@@ -36,6 +36,38 @@ int main() {
   assert(status_text(curtain) == "Open · 100%");
   assert(status_text(shutter) == "Closed");
 
+  // The cover card (firmware 0.2.50+). Motionblinds venetian blinds report every feature (255).
+  Tile blind = make("cover.venetianblind_0001", "open", 255); blind.device_class = "blind"; blind.position = 60; blind.edit_extra().tilt = 40;
+  CoverCard card = cover_card(blind);
+  assert(card.position && card.tilt && card.keys && !card.tilt_keys);
+  assert(cover_card_status(blind) == "Open · 60% · Tilt 40%");
+  assert(cover_keys(blind, keys) == 3 && !strcmp(keys[0].icon, glyph::UP) && !keys[0].disabled && !keys[2].disabled && !keys[2].checked);
+  blind.state = "closing";
+  assert(cover_keys(blind, keys) == 3 && keys[2].checked && !keys[0].checked);
+  assert(cover_tilt_keys(blind, keys) == 3 && keys[0].command == COVER_OPEN_TILT && keys[2].command == COVER_CLOSE_TILT);
+  assert(key_action(blind, COVER_OPEN_TILT).service == "cover.open_cover_tilt");
+  assert(key_action(blind, COVER_STOP_TILT).service == "cover.stop_cover_tilt" && key_action(blind, COVER_CLOSE_TILT).service == "cover.close_cover_tilt");
+  CoverCard curtain_card = cover_card(curtain);
+  assert(curtain_card.position && !curtain_card.tilt && curtain_card.keys && !curtain_card.tilt_keys);
+  assert(cover_card_status(curtain) == "Open · 100%");
+  // A garage door: open, stop and close only; close is disabled while it is closed.
+  Tile garage = make("cover.garage", "closed", 11); garage.device_class = "garage";
+  CoverCard garage_card = cover_card(garage);
+  assert(!garage_card.position && !garage_card.tilt && garage_card.keys && !garage_card.tilt_keys);
+  assert(cover_keys(garage, keys) == 3 && keys[2].disabled && !keys[0].disabled);
+  // Slats that tilt without a position get tilt keys; a key that cannot tilt further is disabled.
+  Tile slats = make("cover.slats", "open", 3 | 16 | 32); slats.edit_extra().tilt = 100;
+  CoverCard slats_card = cover_card(slats);
+  assert(slats_card.tilt_keys && !slats_card.tilt && !slats_card.position);
+  assert(cover_tilt_keys(slats, keys) == 2 && keys[0].disabled && !keys[1].disabled);
+  assert(cover_card_status(slats) == "Open");
+  // Features not reported yet: the card offers the three keys, a tile's key row stays empty as before.
+  Tile unknown = make("cover.new", "unknown", 0);
+  CoverCard unknown_card = cover_card(unknown);
+  assert(unknown_card.keys && !unknown_card.position && cover_keys(unknown, keys) == 3);
+  unknown.controls = "buttons";
+  assert(keys_for(unknown, keys) == 0);
+
   // Vacuum: play while docked, pause while cleaning, dock disabled in the dock.
   Tile robot = make("vacuum.s8", "docked", 30524); robot.controls = "buttons";
   assert(keys_for(robot, keys) == 3);