Scaffold the Go project, CLI skeleton, and cloud authentication

[berendt]

Closes #2

Summary

Lays down the repository foundation that every other package will build on: a Go module, the cmd / internal package layout, a cobra-based CLI exposing the neutron command namespace, and clouds.yaml-based authentication that yields a working gophercloud v2 NetworkV2 client. Global flags, structured logging, and CI (build, vet, lint, test) are wired here, and the previously-open module-path and CLI-framework decisions are settled.

Demoable on its own: neutron --help lists the subcommands, and neutron list-networks authenticates against the configured cloud and issues one trivial NetworkV2 call as an end-to-end auth/connectivity smoke test.

Change set (in commit order)

1. 5b653dc Initialize Go module and add .gitignore — Adds go.mod (module github.com/B42Labs/openstack-tester, go 1.26.1) with the gophercloud/gophercloud/v2 and spf13/cobra direct dependencies plus the resolved go.sum, and a .gitignore covering the built binary, Go test/coverage artifacts, and editor/OS files.

2. bce2f01 Add config package for clouds.yaml NetworkV2 auth — Introduces internal/config with NewNetworkClient(ctx, cloudName). It parses clouds.yaml (selecting the cloud from OS_CLOUD when cloudName is empty), builds an authenticated provider client with TLS config, and returns a NetworkV2 service client, wrapping every failure path with context. Ships a unit test (config_test.go) covering the no-cloud and missing-file error paths, and an integration-tagged test (config_integration_test.go) that exercises a real cloud, skipped unless OS_CLOUD is set.

3. 8e6e2a2 Add cobra CLI skeleton with neutron stub subcommands — Adds the cmd/openstack-tester binary: main.go (root command execution with a context.Background()), root.go (root command, the --os-cloud / --concurrency / --timeout / --seed / --log-level persistent flags, and slog-based structured logging configured in PersistentPreRunE), neutron.go (the neutron namespace with generate, apply, status, report, cleanup, and verify stubs that return a not-implemented error), and list_networks.go (a working list-networks subcommand wired to internal/config). root_test.go asserts subcommand/flag registration, log-level parsing, that neutron --help runs, and that the stubs return errors.

4. 25cf16e Add CI workflow for build, vet, lint, and test — Adds .github/workflows/ci.yml (a build job running go build/go vet/go test and a lint job running golangci-lint, both pinned by commit SHA and reading the Go version from go.mod) plus a minimal v2-schema .golangci.yml.

5. 9d11432 Record resolved module-path and CLI decisions in README — Updates the README status to "Phase 1 in progress" and marks the two open decisions as resolved: CLI framework is cobra, and the module path is github.com/B42Labs/openstack-tester at the repository root.

Notes / divergences from the issue

• Module path & layout — The issue's design doc floated github.com/osism/testbed/contrib/openstack-tester under a contrib/ directory as a candidate. This branch resolves the open decision to github.com/B42Labs/openstack-tester with the module at the repository root (no contrib/), and records that in the README.
• CI scope — The issue asks for "build, lint, vet"; the workflow additionally runs go test ./.... That is a superset of what was requested and keeps the unit tests gated in CI.
• list-networks — Beyond the six stub subcommands, neutron list-networks is implemented as a real read-only NetworkV2 call. This is the "trivial API call such as listing networks" the issue names as the demo criterion, rather than an extra feature.

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Implemented by planwerk-review a24f4d9 with Claude:claude-opus-4-8