Contributor mode never fired in 18 days of heavy use (required manual opt-in
via gstack-config, gated behind _CONTRIB=true, wrote disconnected markdown).
Removes: generateContributorMode(), _CONTRIB bash var, 2 E2E tests, touchfile
entry, doc references. Cleans up skip-lists in plan-ceo-review, autoplan,
review resolver, and document-release templates.
The operational self-improvement system (next commit) replaces this slot with
automatic learning capture that requires no opt-in.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
b6fcfd84b7