refactor: reuse constants for redis db

go/internal/db/redis.go

@@ -0,0 +1,8 @@
+package db
+
+// Shared database namespaces used across services
+// FIX: Use separate redis instance. We start with higher number because use this same instance in helios.
+const (
+	RedisDBAuth   = 4 // auth sessions
+	RedisDBPusher = 5 // dedicated to pusher state (presence, pub/sub)
+)