PR #153 rebase accidentally reverted ci.yml to pre-optimization state due to inverted --ours/--theirs semantics during git rebase. This restores all optimizations from PRs #150-#153: - Job timeouts on all jobs - Composite setup action (.github/actions/setup/) - Lexicons build caching - Next.js build cache (shared between build and accessibility) - Job dependency graph (lint/typecheck/test -> build -> accessibility) - Path filters for PRs (skip CI on docs-only changes) - --prod flag on security audit