xfy aaeb9c2c49 ci: add GitHub Actions CI pipeline
Add continuous integration workflow triggered on push to master
and pull requests.

Jobs:
- lint: gofumpt format check + golangci-lint v2 via action
- test: unit tests with -race flag (no integration/e2e)
- build: static multi-platform build (linux/darwin, amd64/arm64)
  with ldflags version injection, binary upload as artifact
- docker: docker buildx build (only on push to master/tags)

Uses:
- actions/checkout@v4, actions/setup-go@v5, golangci/golangci-lint-action@v7
- Go version auto-detected from go.mod (1.26)
- Module caching for faster CI runs
2026-06-11 23:42:00 +08:00
..
2026-06-11 23:42:00 +08:00