Shell completions for basectl gh issue still reference --type instead of --category

[codeforester]

Problem

gh.sh was updated to replace --type with --category and the label set from feat|fix|chore|docs to bug|enhancement|documentation|ci|security, but neither completion file was updated.

Bash (lib/shell/completions/basectl_completion.sh, gh issue case):

_base_basectl_completion_compgen "--type --title --body -h --help" "$cur"

--type should be --category.

Zsh (lib/shell/completions/basectl_completion.zsh, line 106):

'--type[Issue or branch type]:type:(feat fix chore docs)'

Should be:

'--category[Issue category]:category:(bug enhancement documentation ci security)'

Impact

Anyone using tab completion for basectl gh issue create or basectl gh issue start gets the wrong flag name suggested and the wrong values. Completing --type passes an unknown option to the updated base_gh_issue_create function, which would error.

Fix

Update both completion files to replace --type with --category and the value list with bug enhancement documentation ci security.

Also update skills.md's "Add a basectl subcommand" section reminder: when changing a subcommand's flags, update the completions.