docs(redteam): redteam targets delete — root-cause sub-issue

## Command
airs redteam targets delete

## Invocation tried
```
airs redteam targets delete 00000000-0000-0000-0000-000000000001
```

## Observed error
```
  Error: AISEC_CLIENT_SIDE_ERROR:License has expired. Only read-only access is allowed.

EXIT=1
```

## Root cause
license-blocked

## Tracking
Existing umbrella: #123