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>

README.md

@@ -85,6 +85,10 @@ The firmware and built-in CLI are tested with **ESPHome 2026.6.2**.
   uses are shown (app 0.2.46 / firmware 0.2.39).
   Scenes, scripts, and buttons show when they last ran. A tile that's waiting on
   Home Assistant shows a small spinner on a light overlay.
+- **Cover card** for blinds, curtains, shutters, and garage doors, like Home Assistant's own:
+  a tall position slider on which the blind hangs from the top, a tilt slider over slats for
+  venetian blinds, open, stop, and close, and the battery of a battery-powered blind
+  (such as Motionblinds). A cover shows only what it supports (app 0.2.58 / firmware 0.2.50).
 - **Top bar per screen** (firmware 0.2.32+): the name on the left, up to six
   items of your choice on the right: the time, an analog clock, the date, or an
   entity from Home Assistant with an icon, such as temperature, humidity, power usage, a door
@@ -120,8 +124,14 @@ The firmware and built-in CLI are tested with **ESPHome 2026.6.2**.
   <img src="docs/images/guition-page-3.png" width="32%" alt="Curtains with open, stop and close, a kitchen timer counting down, a scene and the sun path">
 </p>
 <p align="center">
-  <img src="docs/images/cyd-vacuum.png" width="40%" alt="The vacuum card on the CYD: state, battery and charging, clean and dock, the cleaning mode, suction and water">
-  <img src="docs/images/cyd-climate.png" width="40%" alt="The climate card on the CYD: the target temperature with big minus and plus keys and one row of mode keys">
+  <img src="docs/images/guition-blind.png" width="32%" alt="Cover card for a venetian blind: its battery, the position slider with the blind hanging from the top, the tilt slider over slats, and open, stop and close">
+  <img src="docs/images/guition-curtains.png" width="32%" alt="Cover card for curtains: the position slider and the sideways open, stop and close keys">
+  <img src="docs/images/guition-garage.png" width="32%" alt="Cover card for a garage door that only opens and closes: its icon and the open, stop and close keys, close disabled while it is closed">
+</p>
+<p align="center">
+  <img src="docs/images/cyd-vacuum.png" width="32%" alt="The vacuum card on the CYD: state, battery and charging, clean and dock, the cleaning mode, suction and water">
+  <img src="docs/images/cyd-climate.png" width="32%" alt="The climate card on the CYD: the target temperature with big minus and plus keys and one row of mode keys">
+  <img src="docs/images/cyd-blind.png" width="32%" alt="The cover card on the CYD: the position and tilt sliders with their values beside them, the battery, and open, stop and close">
 </p>
 
 Features depend on the capabilities Home Assistant reports for an entity.