Trim is not the word one would use and I’m not sure about cabin either. Is the thing being used something that can travel with someone? A cabin is a permanent structure.

Cabin can be either larger wooden house in the mountains made of wood usually or it can also be a small cabin in the mountains or hills. Wood trims are trims ( off cuts)of wood usually used for interior decoration…flooring is most common, door frames , but in mountains it can be all over the interior walls, similar to sauna. I am not quite sure what you are trying to describe, hope this helps.

Yes, cabin is a room on a ship. It can also be a form of structure on land. Trim means the opposite of fat. Perhaps you meant to say a narrow cabin

A neat cabin would be better, but look at the answers to your other question about a neat or trim yacht. Without more context (if there is any?) a trim cabin could possibly/potentially be correct in a naval boating context. However you small sentence out of context is slightly weird. A neat cabin is what is expected to express being tidy, smart or possibley cool. Neat then being used as a slang-ish word equal to "a cool cabin".