feat: complete migration to config flow and bugfixes (@38decibel)

* feat: migrate to config flow with device registry and brand icons

- Migrate all platforms to async_setup_entry (config flow)
- Each device now appears as a real HA device in the device registry
- Add device_info to all entities (cover, switch, button, sensor, binary_sensor)
- Add config_flow.py with airsend.yaml + !secret resolution
- Add strings.json for UI labels
- Fix unique_id bug (was splitting each character of the name)
- Split binary_sensor.py from sensor.py
- Bump version to 4.0

* Add icon for local brand

* Revise installation steps for AirSend integration

* Correction du crash websocket

raise Exception remplacé par return False

* Update README with AirSend configuration steps

Added instructions for configuring AirSend in Home Assistant.

* Update README with clearer instructions for YAML

Clarified instructions for editing the airsend.yaml file.

* Add files via upload

* Add English translation for AirSend configuration

* Add fr translations

* Update screenshot following latest version

* Fixe unavailable and new type light

Corrections de bugs
500 avec wait: true non fatal

Nouveau type
light.py — lumière dimmable (type 4100)

custom_components/airsend/manifest.json

@@ -3,9 +3,9 @@
   "name": "AirSend",
   "documentation": "https://github.com/devmel/hass_airsend",
   "dependencies": ["http"],
-  "config_flow": false,
+  "config_flow": true,
   "codeowners": ["@devmel"],
   "requirements": [],
-  "version": "3.4",
-  "iot_class": "cloud_polling"
+  "version": "4.0",
+  "iot_class": "local_push"
 }