Inserting robot moves into an SQLite3 database
Just a philosophical answer here.

I think you're asking the wrong question. You shouldn't ask yourself "is my SQL code safe or vulnerable?" This is too hard to answer in any individual case, and coming up with the right answer could depend on a lot of contextual things such as the system configuration, the whole program structure, etc.

You don't want to have to consider all these things when writing code. People have already considered them a lot, and based on their experience they have come up with best practices.

Instead you should ask the question,


  Does my code follow the standard best practices for preventing SQL injection?


As alluded to in another answer, using string interpolation to build queries is against best practices. So, while it doesn't seem like this creates a vulnerability in your code, we can't rule out that there is some edge case based on the rest of your program structure that would allow an attacker to put something into this string interpolation.

Unless you have a very good reason for doing so, follow the best practices, even if you don't need to. Then you can sleep well and ignore pathological edge cases.