chore: migrate dependency updates from Dependabot to Renovate

[ivorisoutdoors]

What changes for dependency PRs

• Who opens them: the org Renovate GitHub App instead of dependabot[bot].
• When: monthly → monthly, on the 1st (UTC). Tick an update in the Dependency Dashboard issue to get it early.
• Grouping: github-actions dependencies. Major updates land in the same PR.
• Coverage: newly updated: none. No longer updated: none.
• Versions: Renovate bumps the range in the manifest, not only the lockfile. It leaves engines, the Go go directive, requires-python, and Terraform required_version alone.
• Limits: no cap on open PRs.
• Labels and commits: renovate and dependencies labels; semantic commit messages.
• Dropped: commit-message.prefix: ci: the repo has no release tooling, so the preset's semantic commits apply. groups.actions (patterns: ["*"]): the org default already groups every GitHub Actions update into one PR. directory: Renovate scans the whole repo.
• Security updates: Dependabot security updates are a repo setting and keep running if enabled.

After merging

• Add the renovate topic so the org Renovate operator picks up this repo: send @Botzo repo topic add renovate to articulate/docker-node in Slack. Nothing opens until the topic is set. Re-running it is harmless.

Notes

• The dockerfile manager is off because each image pins its base-image major on purpose (20/, 22/, 24/, 26/), so Renovate would open unwanted cross-major bumps for the FROM lines.
• .github/workflows/auto-merge.yaml approves and auto-merges PRs from dependabot[bot] or articulate-automation[bot]. This PR leaves it unchanged. Renovate PRs auto-merge only if the org Renovate app's login is articulate-automation[bot]; otherwise update the if: condition in a follow-up.

[ivorisoutdoors]

Superseded by a rerun on chore/migrate-dependabot-to-renovate-r2 after a skill fix (articulate/org-renovate#28).