fix(webhook): reject unsupported endpoint URL schemes

[rambhardwajj]

Description

This pull request fixes webhook endpoint URL validation by rejecting unsupported URL schemes such as ftp:// and file://.

Previously, the CLI only validated URL parsing and host validity through utils.ValidateURL, but it did not restrict the URL scheme. As a result, unsupported schemes could pass client-side validation and proceed toward the Harbor API request.

This change ensures webhook endpoint URLs only allow http and https schemes during CLI-side validation.

• Fixes [bug]: Webhook endpoint URL validation accepts unsupported schemes like ftp:// #937

Type of Change

Please select the relevant type.

• Bug fix
• New feature
• Refactor
• Documentation update
• Chore / maintenance

Changes

• Added utils.ValidateHTTPURL to validate URLs and restrict schemes to http and https
• Updated webhook create/edit command validation to use HTTP(S)-only URL validation
• Updated webhook create/edit interactive views to use the same validation
• Added tests covering unsupported schemes such as ftp:// and file://
• Regenerated CLI documentation with dagger call run-doc export --path=./doc; no documentation changes were produced