Aside from repairing via trader, is there any other way to repair ship hull? I've just started playing a while ago, and can't seem to find any way to repair ship hulls apart from in stores. Is there some kind of augmentation or weapon?
There is an augmentation called the Repair Arm. Every time you collect scrap it heals your hull for 1-2 points of damage, but at a cost of 15% of the scrap you would have collected.
This augmentation is often considered rather poor, since the repairs are not cost effective when compared to repairing at a store, it deducts the 15% of scrap even if your hull is fully repaired, and it also takes up an augmentation slot which could be used for something much more useful.
There is also a drone which repairs hull damage, the Hull Repair Drone. This is a 2-power drone which, when deployed, heals 3-5 points of hull damage. A new drone part is required for every use of the drone.
This drone is considered to be very helpful in between stages of the Rebel Flagship, since you may be in need of repair but unable to find a store/repair station before having to battle the next stage. You can even keep the schematic for this drone in your storage when not needed, and have more combat oriented drones active, swapping this one in after the fight is complete.
There are also random events and encounters which can repair your hull. You might complete a quest, the reward for which is some hull repair. You can also encounter small repair stations which can repair your hull for scrap as you would see in a store.