I finally got the phq and it doesn't have any shields or seem to have a way to repair hull damage. I bought blueprints for L/XL shields but can't seem to add them to my phq. Is there a different blueprint I need, is there some other way to install shields or is there simply no way to fix the phq?

The sector the player is in seems to get hit by waves of attacks every 5 minutes when I am in my phq but when I leave the sector the attacks stop. Do I have to stay out to keep my phq alive or am I missing something?

I waited several hours real time and no drones appeared in the station overview but then I assigned 2 trade ships to the station and within 5 minutes I suddenly had drones. I don't know if it just took that much time or if the trade ship is required to supply the station with repair (and defense) drones. So far my station hull is still 99% but I just got the drones. I'll wait a few more hours and see if the repair drones actually repair the hull.

Update. Several hours with 12 repair drones and hull still at 99%. May not be enough damage to trigger repair. Its odd but I havent had a single attack in all the hours since my player left the phq and the sector entirely. Maybe thats the only thing you can do to protect the phq. I still have 2 heavy fighters and 4 M class ships protecting the station still- just in case the attacks start again.