Add kettle preset selects (#4972)
## Summary
Adds optional DP106 and DP107 preset select entities to the existing
Korex AX-WF306N kettle config.
This is a device-config-only PR. No Python code changes are included.
## Why
The existing config already covers the core kettle functions. The same
product also exposes two additional preset controls:
- `106`: Boil preset
- `107`: Boil and cool preset
These are separate from the existing DP101 temperature control and
appear to be app-style preset selections.
## Tested device
- Manufacturer/model: Korex AX-WF306N / Kogan smart kettle variant
- Product ID / productKey: `2vuvtw0cj8wmjrpc`
- Protocol/interface used locally: `3.3`
## Existing config
The existing Tuya Local config already supports this product ID as a
kettle using DPs `1`, `5`, `10`, `101`, `102`, `103`, `104`, and `105`.
## Added datapoints
- `106`: Boil preset
- `107`: Boil and cool preset
## Validation
- Tested locally with LocalTuya-style DP mapping
- Existing power, current temperature, keep-warm, and status behavior
work
- DP106 exposes boil preset options
- DP107 exposes boil-and-cool preset options
- No local keys, device IDs, IP addresses, or private account data are
included
## Reference
Original Home Assistant community post documenting the LocalTuya setup
and DP106/DP107 usage:
https://community.home-assistant.io/t/korex-ax-wf306n-smart-kettle-works-perfectly-with-localtuya/909674
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Co-authored-by: Jason Rumney <make-all@users.noreply.github.com>