pop starships, specifically leech starships in and out of the wormhole, just long enough to fire a salvo and escape before the mass driver does too much damage. this will cause all the nearby ships to a) be marked for reclaimation and b) be freed, and to attack you. they attack you, you capture them, the AI garrison is reduced. repeat this until nothing is nearby.
capture an adjacent planet and build lots of FF. send them all through the wormhole to the enemy system with your fleet inside. shred all the enemy ships that attack the FF until the garrisoning AI ships are gone, then use mass bombers to take down shields. have your spaceports on the adjacent planet rapidly replacing losses and rallying to the AI homeworld so reinforcements are constant.
hope this helps