feat: initial scaffold of unibus message bus (membership service + client lib + demo peers)

pkg/membership/ulid.go

@@ -0,0 +1,13 @@
+package membership
+
+import (
+	"crypto/rand"
+
+	"github.com/oklog/ulid/v2"
+)
+
+// newULID returns a fresh, lexicographically-sortable unique id used for room
+// ids. It uses crypto/rand entropy so ids are unguessable and collision-free.
+func newULID() string {
+	return ulid.MustNew(ulid.Now(), rand.Reader).String()
+}