Publish pipeline: goreleaser + Maven Central + npm (#1)

* feat(cli): add Version var and version subcommand

* build(gradle): introduce uatu.version property for lockstep releases

* build(sdk-android): swap GitHub Packages for vanniktech Maven Central plugin

* build(spec-api): make package publish-ready for npm

* ci(release): add goreleaser config for cross-platform uatu CLI builds

* ci: add ci and release GitHub Actions workflows

* ci: restrict ci.yml to PR + workflow_dispatch (no direct push to master)

* docs(release): add local release targets, env example, and install docs

* build(sdk-android): make signAllPublications conditional on signing key

* ci(release): stage sidecar JAR at embed path before go build

* chore(spec-api): regenerate package-lock for updated package.json

* ci: install protoc-gen-go plugins before buf generate

* ci: bump Node to 22 (required for --experimental-strip-types)

cmd/uatu/main_test.go

@@ -95,6 +95,22 @@ func TestRun_HelpPrintsUsage(t *testing.T) {
 	}
 }
 
+func TestRun_VersionPrintsVersion(t *testing.T) {
+	prev := Version
+	Version = "1.2.3-test"
+	defer func() { Version = prev }()
+
+	for _, arg := range []string{"version", "--version", "-v"} {
+		var stdout bytes.Buffer
+		if err := run([]string{"uatu", arg}, &stdout, io.Discard); err != nil {
+			t.Fatalf("%s: %v", arg, err)
+		}
+		if strings.TrimSpace(stdout.String()) != "1.2.3-test" {
+			t.Errorf("%s: got %q, want 1.2.3-test", arg, stdout.String())
+		}
+	}
+}
+
 func TestRun_UnknownCommand(t *testing.T) {
 	err := run([]string{"uatu", "wat"}, io.Discard, io.Discard)
 	if err == nil || !strings.Contains(err.Error(), "unknown command") {