One of my favorites - you managed fit some nice characterization of both the ship and the captain into the format. I enjoyed the nods to other aspects of the setting: past conflicts against the Starhost, the Legion as liberators of the ship AI.
And the sci-fi brushstrokes with which you paint the story are satisfying. I found myself grinning at the banter between Holly (love the shortening of the ship name) and the captain regarding the background temperature. The marine vital signs tooks me back to Aliens, while the refusal of the ship to allow the shutdown was reminiscent of another AI sharing the same first initial.
Overall a story that I very much enjoyed - it left me wanting to read more!