ci: Make consumer scripts shellcheck-clean and widen lint scope

[rubambiza]

Summary

The test CI added in #35 (.github/workflows/tests.yml) runs shellcheck on the library modules only (core.sh, github-api.sh, fork.sh, org.sh, program-lib.sh) at --severity=warning. The consumer program scripts are not yet shellcheck-clean, so they are deliberately excluded from the lint step for now. This issue tracks bringing them up to standard and widening the lint scope.

Current state

shellcheck scripts/*.sh at --severity=warning reports 19 SC2034 (unused variable) warnings across seven consumer scripts, plus a few info-level notices:

File	SC2034 count
automation-health-dashboard.sh	3
dep-bump-fixer.sh	2
dep-bump-scanner.sh	2
link-health-fixer.sh	4
link-health-scanner.sh	4
pr-review-impact.sh	2
pr-review-scanner.sh	2

Most are the arg-parsing idiom where --flag) SOME_FLAG="$2" assigns a variable that a later load_org_profile / resolution step reads indirectly, so shellcheck cannot see the use. Info-level notices (SC2016, SC2153) also appear on a couple of files. The tests/*.sh files carry their own minor warnings (SC2034, SC2163).

Proposed work

• Audit each SC2034: either wire the variable through so its use is visible, or add a scoped # shellcheck disable=SC2034 with a one-line reason at the assignment.
• Resolve or scope the info-level notices in the consumer scripts and the test files.
• Once clean, widen the CI shellcheck step to scripts/*.sh (and optionally tests/*.sh).

Why separate from #35

#35 is a scoped decomposition + portability PR; fixing pre-existing warnings across every consumer script is unrelated cleanup and would violate the repo's scope-discipline rule (CLAUDE.md). Splitting it out keeps #35 reviewable and lets the lint sweep land on its own.