Add Renovate and CI gates

[michaelw]

Summary

• add Renovate configuration matching the dependency managers used in the reference repo
• add required-ready CI jobs for pre-commit, DevSpace config validation, and GitHub Actions linting
• make the smoke workflow run for scheduled/manual runs, PRs labeled smoke, and PRs that touch DevSpace/smoke-related files

Validation

• PRE_COMMIT_HOME=/tmp/devspace-starter-pack-pre-commit pre-commit run --all-files --show-diff-on-failure
• GOCACHE=/tmp/devspace-starter-pack-go-cache GOPATH=/tmp/devspace-starter-pack-go go run github.com/rhysd/actionlint/cmd/actionlint@latest
• devspace print --skip-info --disable-profile-activation >/tmp/devspace-starter-pack-devspace-print.yaml
• PRE_COMMIT_HOME=/tmp/devspace-starter-pack-pre-commit GOCACHE=/tmp/devspace-starter-pack-go-cache GOPATH=/tmp/devspace-starter-pack-go make verify