Fix infinite loop when disabling SimpleSwitch entities (#1296)

* Add regression tests for SimpleSwitch initial state bug

Adds tests that verify SimpleSwitch._state is set immediately in __init__
rather than waiting for async_added_to_hass(). These tests currently FAIL
because _state is None after __init__, which causes an infinite loop in
_setup_listeners when the entity is disabled (since async_added_to_hass
is never called for disabled entities).

Regression tests for: https://github.com/basnijholt/adaptive-lighting/issues/1264

* Fix infinite loop when disabling SimpleSwitch entities

The issue was that SimpleSwitch._state was initialized to None in __init__,
but only set to a boolean value in async_added_to_hass(). When an entity
is disabled, async_added_to_hass() is never called, so _state stayed None.

The _setup_listeners() method has a while loop that waits for
_state is not None for all SimpleSwitch children (sleep_mode_switch,
adapt_brightness_switch, adapt_color_switch). With _state stuck at None,
this created an infinite loop.

The fix sets _state to initial_state directly in __init__ instead of
waiting for async_added_to_hass() to set it. The async_added_to_hass()
will still properly restore state from the last session or set based
on initial_state as before.

Fixes: https://github.com/basnijholt/adaptive-lighting/issues/1264

custom_components/adaptive_lighting/switch.py

@@ -1563,7 +1563,7 @@ class SimpleSwitch(SwitchEntity, RestoreEntity):
         self.hass = hass
         data = validate(config_entry)
         self._icon = icon
-        self._state: bool | None = None
+        self._state: bool = initial_state
         self._which = which
         self._config_name = data[CONF_NAME]
         self._unique_id = f"{self._config_name}_{slugify(self._which)}"