feat!: probes generate their own keys and enroll with a join token; node and peer keys are separate [CI]

backend/src/MoShiro.Backend.Storage.Sqlite/Sql.cs

@@ -56,4 +56,6 @@ internal static class Sql
     public static string? NullableString(this SqliteDataReader reader, int ordinal) => reader.IsDBNull(ordinal) ? null : reader.GetString(ordinal);
 
     public static byte[] Bytes(this SqliteDataReader reader, int ordinal) => (byte[])reader.GetValue(ordinal);
+
+    public static byte[]? NullableBytes(this SqliteDataReader reader, int ordinal) => reader.IsDBNull(ordinal) ? null : (byte[])reader.GetValue(ordinal);
 }