Init Unit

public Unit InitUnit(Unit unit, ISpawnUnitData spawnData, byte playerOwner)

Initializes an already-existing Unit instance (camera state, dependency injection, owner player, etc.), registers it with UnitsService, and fires SpawnedUnit.

Used internally by SpawnUnit, but also useful on its own for units already placed on the map in the Editor (rather than spawned in code) - initialize them with this method once the match starts.