KNX Fan: Add support for switch addresses

[farmio]

Proposed change

This adds support for knx fan entities that either only support switching (on/off binary) or support switching in addition to setting a speed. The actuators default turn-on speed will be respected then.

• requires a release of xknx with Fix Fan turn_on default speed when step-mode is used XKNX/xknx#1775 this is added to HA here Update xknx to 3.13.0 #159371

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue: Update xknx to 3.13.0 #159371 Add support for dedicated switch GA to KNX fan platform #73131
• Link to documentation pull request: KNX Fan: Add support for switch addresses home-assistant.io#42642
• Link to developer documentation pull request:
• Link to frontend pull request:

Checklist

• I understand the code I am submitting and can explain how it works.
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• Tests have been added to verify that the new code works.
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[home-assistant]

Hey there @Julius2342, @marvin-w, mind taking a look at this pull request as it has been labeled with an integration (knx) you are listed as a code owner for? Thanks!

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[Copilot]

Pull request overview

This PR adds support for KNX fan entities that use switch addresses for on/off control, either as the sole control method or in combination with speed control. This allows fans to respect the actuator's default turn-on speed when no specific percentage is provided.

Key changes:

• Refactored async_turn_on and async_turn_off to delegate to the underlying xknx device's turn_on() and turn_off() methods instead of using set_speed()
• Made speed control optional in the schema, requiring at least one of switch or speed configuration
• Updated supported_features to conditionally include SET_SPEED only when speed control is initialized

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
homeassistant/components/knx/fan.py	Refactored turn on/off methods to use device-level commands, added support for switch addresses in UI fan initialization, made speed features conditional
homeassistant/components/knx/storage/entity_store_schema.py	Updated schema to make both switch and speed optional with validation requiring at least one
homeassistant/components/knx/strings.json	Added UI labels and descriptions for the new switch group address field
tests/components/knx/test_fan.py	Added test case for switch-only fan configuration with state verification
tests/components/knx/snapshots/test_websocket.ambr	Updated snapshot to reflect new optional switch field in schema