ea0d90d8f0
Add .woodpecker/pr-build.yaml: builds all three arches (dry-run, no push) on PRs and pushes to main, reporting status to Gitea. This is the gate for automerge. renovate.json automerge rules (platformAutomerge, merged only after the PR build passes): - tailscale stable patch AND minor - Go/Alpine/busybox PATCH only - base-image digest refreshes Minor/major of build deps and tooling stay manual. Move pinDigests into a dockerfile packageRule (top-level dockerfile.* is deprecated). Document the automerge policy and its caveat (PR build proves build-only, not runtime) in DESIGN.md.