This has been discussed before.
If the question is about a general EE topic that just happens to be in the context of an Arduino project, it stays here in EE.SE.
If the answer to the question requires knowledge that is specific to the Arduino hardware or software development environment, it gets migrated to Arduino.SE.
In some cases, it's a judgement call, but I do my best (and I'm sure the other moderators do, too) to make sure I understand the question before deciding whether to migrate it.
That said, in the specific case of the question you cite, the fact that the OP would even consider packaging a breadboard as a permanent solution was a big red flag that he is a complete beginner to begin with. This indicated to me that the answers he would get from the Arduino community would be a much better match for him than the answers he would get here. I'm pretty sure that they have already addressed the issue of making an Arduino project "permanent" many times before, and that there are products specific to that environment that make it easier.
Keep in mind that in some senses, Arduino is the opposite of EE. EE is all about understanding the low-level details of how a circuit and the associated firmware works, so that you can build similar, but different functionality in the future. On the other hand, Arduino is all about hiding those low-level details so that a developer can focus on the high-level functionality of his project.
Some people start on Arduino and then try to bridge the gap to EE. It's possible to do this, but it can be somewhat of an uphill battle until that person has a good grasp of basic principles of electricity and digital logic.