Explain why masked CI variable value length must be at least 8
Originally mentioned [in Slack](https://gitlab.slack.com/archives/C3JJET4Q6/p1717410937673449) (internal).
If you try to create a masked CI variable with less than eight characters, an error (**The value must have at least 8 characters.**) will be shown. This is specifically related to masked CI variables but this is not explained, unlike for values that contain e.g. a linebreak.
| Length | Whitespace |
| ------ | ---------- |
| {width=388 height=138} | {width=390 height=153} |
## Proposal
Show the info prefix `This value cannot be masked because it ...` in cases where the value is too short to be masked.
This is already the case when the value contains an invalid character, e.g.:
{width=388 height=175}
## Implementation plan
The message is assembled in `app/assets/javascripts/ci/ci_variable_list/components/ci_variable_drawer.vue`, specifically the `maskedValueMinLengthValidationText` and `unsupportedCharsValidationText` computed variables.
issue