# GRM-172: Audit and document pre-pull image usage guidelines

## Problem
The grm repo contains a runner-level `pre_pull_images.yml` task file that
pre-pulls Docker images to avoid repeated pulls on every CI run. However,
there was no audit confirming that molecule `prepare.yml` files are not
also redundantly pre-pulling images that the runner setup already caches.
Wasteful pre-pulling wastes CI time and disk space.

## Approach
Audit all molecule `prepare.yml` files in the grm repo for pre-pull tasks.
The audit found NO molecule prepare.yml files contain pre-pull tasks, so no
code removal is needed. Document the audit findings in a spec and add a
comment to the runner-level `pre_pull_images.yml` task file clarifying that
it should not be used for images that molecule tests pull themselves (to
avoid redundant pulls).

REQ-1: Audit all molecule prepare.yml files for pre-pull tasks and confirm none exist
REQ-2: Add documentation comment to pre_pull_images.yml stating it should not be used for CI runner container images (already cached by runner setup) or images molecule tests pull themselves
REQ-3: Confirm gitea_runner_pre_pull_images default remains empty ([]) which is correct

## Test Plan
- Grep all molecule prepare.yml files for pre-pull patterns confirms zero matches
- Verify pre_pull_images.yml comment is present and accurate
- Verify gitea_runner_pre_pull_images default is [] in defaults/main.yml
- Run make lint-ci to confirm no lint regressions

## Deploy Plan
- Merge to master via auto-merge workflow
- No runtime changes; documentation-only

## Rollback Plan
- Revert the merge commit; comments are removed, no functional impact

## Acceptance Criteria
- [x] REQ-1: No molecule prepare.yml files in the grm repo contain pre-pull tasks (audit confirmed via grep)
- [x] REQ-2: pre_pull_images.yml contains a comment documenting it should not be used for CI runner container images or images molecule tests pull themselves
- [x] REQ-3: gitea_runner_pre_pull_images default remains empty ([]) in defaults/main.yml