Onboard Horizon DB to Azure CLI

Information required from service team:

**Resource provider. What is the Azure resource provider your feature is part of?**
Microsoft.HorizonDb

**Description of feature or work requested. Provide a brief description of the feature or work requested. A link to conceptual documentation may be helpful too.**
Commands associated to HorizonDb using Python SDK azure-mgmt-horizondb 1.0.0b1

- horizondb create
- horizondb update
- horizondb delete
- horizondb show
- horizondb list
- horizondb restore
- horizondb firewall-rule delete
- horizondb firewall-rule list
- horizondb firewall-rule show
- horizondb firewall-rule update
- horizondb deploy setup
- horizondb deploy run
- horizondb parameter list
- horizondb parameter set
- horizondb parameter show
- horizondb replica create
- horizondb replica delete
- horizondb replica list
- horizondb replica promote
- horizondb private-endpoint-connection approve
- horizondb private-endpoint-connection delete
- horizondb private-endpoint-connection list
- horizondb private-endpoint-connection reject
- horizondb private-endpoint-connection show
- horizondb private-link-resource list
- horizondb private-link-resource show

**Minimum API version required. What is the minimum API version of your service required to implement your feature?**
2026-01-20-preview

**Swagger link. Provide a link to the location of your feature(s) in the REST API specs repo. If your feature(s) has corresponding commit or pull request in the REST API specs repo, provide them. This should be on the master branch of the REST API specs repo.**
https://github.com/Azure/azure-rest-api-specs/tree/main/specification/horizondb/resource-manager

**Target date. If you have a target date for releasing this feature/work, please provide it. While we can't guarantee these dates, it will help us prioritize your request against other requests.**
June 2026

**Where do you want the feature to locate? A command module or an extension? Here is a [Comparison](https://eng.ms/onboarding/azurecli/modules_and_extensions).**
Command module

**Status of the service. Is it in preview or GA?**
Preview

**Examples of the feature. Usually REST API specs repo should contain examples. An independent documentation or tutorial is also OK.**
https://github.com/Azure/azure-rest-api-specs/tree/main/specification/horizondb/resource-manager/Microsoft.HorizonDb/HorizonDb/examples/2026-01-20-preview

Prerequisite to use this feature. Whitelisting subscription? Registering the feature for subscription? Is it available in public Azure?
Currently whitelisted subscriptions. By June public preview in Azure