Weekly Goal - Maintain weight

Unfortunately it’s almost impossible to gain muscle without gaining some fat. To gain muscle and keep body fat gains to a minimum your diet and exercise routine must be perfect. What’s your body fat %?

Adding muscle while maintaining weight is called recomp these days - it just used to be called "getting in shape".
And it's been done by millions of people who have never heard of recomp or tracked a calorie.
It's just your body's totally normal reaction to an effective training stimulus while supported by an adequate diet.

There's a long running thread in the Maintaining weight forum with plenty of examples -
https://community.myfitnesspal.com/en/discussion/10177803/recomposition-maintaining-weight-while-losing-fat/p1

And no you don't need a calorie surplus to gain muscle although it may make the process quicker. Bulking and cutting cycles are not required by people who don't have very high physique goals - they may be a choice but not a requirement.

And no you don't need a perfect diet, a perfectly normal diet will do although a higher than normal protein intake can be helpful for people training hard with aim of gaining muscle.