Need support for HLK-LD2461

**Describe the problem you have/What new integration you would like**
I have come across this radar sensor HLK-LD2461 and found to be very good on specs and it improves the already supported models such as LD2410, LD2420 and LD2450 etc.

**Please describe your use case for this integration and alternatives you've tried:**
Usecase here is to get a better and upgraded hardware for human presense detection.

**Additional context**
Device details:
https://hlktech.net/index.php?id=1185
https://drive.google.com/drive/folders/14_KgZpL4Th2LTRuq_W0X_ePjHu_Z6lcS

Begin by reviewing the HLK-LD2461 product page and the linked Google Drive materials, then compare its protocol and capabilities with the already supported LD2410, LD2420, and LD2450 models. Done means the device is supported for human-presence detection, but the issue does not name implementation files, tests, or a specific entry point.

Written by the indexing model from the issue text.