AI Task integration (#145128)

* Add AI Task integration

* Remove GenTextTaskType

* Add AI Task prefs

* Add action to LLM task

* Remove WS command

* Rename result to text for GenTextTaskResult

* Apply suggestions from code review

Co-authored-by: Allen Porter <allen.porter@gmail.com>

* Add supported feature for generate text

* Update const.py

Co-authored-by: HarvsG <11440490+HarvsG@users.noreply.github.com>

* Update homeassistant/components/ai_task/services.yaml

Co-authored-by: HarvsG <11440490+HarvsG@users.noreply.github.com>

* Use WS API to set preferences

* Simplify pref storage

* Simplify pref test

* Update homeassistant/components/ai_task/services.yaml

Co-authored-by: Allen Porter <allen.porter@gmail.com>

---------

Co-authored-by: Allen Porter <allen.porter@gmail.com>
Co-authored-by: HarvsG <11440490+HarvsG@users.noreply.github.com>

tests/components/ai_task/test_entity.py

@@ -0,0 +1,39 @@
+"""Tests for the AI Task entity model."""
+
+from freezegun import freeze_time
+
+from homeassistant.components.ai_task import async_generate_text
+from homeassistant.const import STATE_UNKNOWN
+from homeassistant.core import HomeAssistant
+
+from .conftest import TEST_ENTITY_ID, MockAITaskEntity
+
+from tests.common import MockConfigEntry
+
+
+@freeze_time("2025-06-08 16:28:13")
+async def test_state_generate_text(
+    hass: HomeAssistant,
+    init_components: None,
+    mock_config_entry: MockConfigEntry,
+    mock_ai_task_entity: MockAITaskEntity,
+) -> None:
+    """Test the state of the AI Task entity is updated when generating text."""
+    entity = hass.states.get(TEST_ENTITY_ID)
+    assert entity is not None
+    assert entity.state == STATE_UNKNOWN
+
+    result = await async_generate_text(
+        hass,
+        task_name="Test task",
+        entity_id=TEST_ENTITY_ID,
+        instructions="Test prompt",
+    )
+    assert result.text == "Mock result"
+
+    entity = hass.states.get(TEST_ENTITY_ID)
+    assert entity.state == "2025-06-08T16:28:13+00:00"
+
+    assert mock_ai_task_entity.mock_generate_text_tasks
+    task = mock_ai_task_entity.mock_generate_text_tasks[0]
+    assert task.instructions == "Test prompt"