Publish bulk arrays with single evals

[codeforester]

Summary

• build prepend, remove, and unique results in local arrays before one publication eval
• publish positional and repeatable argument arrays with one eval each
• preserve empty-array and nounset behavior while removing O(n) eval loops

Validation

• bats lib/bash/list/tests/lib_list.bats lib/bash/arg/tests/lib_arg.bats
• shellcheck --severity=warning lib/bash/list/lib_list.sh lib/bash/arg/lib_arg.sh

Fixes #285