jf docker scan fails with "is not a docker command" when --min-severity flag is used without a value

Describe the bug

The jf docker scan command fails with the misleading error message docker: 'dsl.exampl.com:5002/app:1.18.4' is not a docker command when the --min-severity flag is provided but no value is specified. This behavior prevents the user from receiving an immediate, clear error about the missing value for the flag. Instead, it seems to cause the command to be incorrectly parsed and passed to the underlying Docker client. Discovered in a CI/CD pipeline where the MIN_SEVERITY variable was not set.
This bug makes debugging difficult when running in a pipeline as the error message points to the wrong root cause.

Current behavior

jf docker scan dsl.example.com:5002/app:1.18.4 --min-severity docker: 'dsl.example.com:5002/app:1.18.4' is not a docker command. See 'docker --help' exit status 1

Reproduction steps

jf docker scan dsl.example.com:5002/app:1.18.4 --min-severity docker: 'dsl.example.com:5002/app:1.18.4' is not a docker command. See 'docker --help' exit status 1

Expected behavior

Error: the --min-severity flag requires a value

JFrog CLI version

2.78.2

Operating system type and version

Linux, MacOs

JFrog Artifactory version

No response

JFrog Xray version

No response

Start at the jf docker scan entry point and reproduce the command with --min-severity but no value using the example image reference. Trace how the flag and image argument are parsed, then verify that the command reports that --min-severity requires a value instead of forwarding the image to Docker.