Maybe Fiasco?

Runecairn hits most of these points mechanically. Stamina is called fatigue and you can take as much as you have free inventory slots before it affects your attributes. Different weapons give you different fatigue causing dodges or attacks. Respawn at bonfires with non-souled enemies respawning. Collect souls and use them for recovery or increasing attributes. It’s designed as as duet or solo game, and doesn’t have the depth of lore that is a hallmark of souls-like games, but you could do it as an emergent lore, or pull from another source. It’s explicitly a post-Ragnarok Norse setting, but sounds like you want more of a Dying Earth setting. Place the mechanics in Worlds Without Number’s Latter Earth or the setting for Vaults of Vaarn (this might be more ruined Earth)? But I find any setting spun with the right atmosphere works better than trying to find a match.

There is also Grave, which is a souls hack of Knave 1e, but I haven’t tryed it.

No interest in 5e. My group did the PF2e started set. Not bad. I enjoyed playing an alchemist bomber. Less fun with a rogue mastermind. I did set up a Honey Heist one-shot for our group on an evening that the regular GM was busy, but too many people had to pull out that we never did it. It does look like a lot of fun.

I’ve been thinking about this a lot. And not just for space combat. Naval combat, too. I don’t have a good answer. I think a single-person fighter dogfights could be done almost the same as person to person tactical ranged combat. Maybe not naval here - tactical Optimist or canoe battle. ;-P Larger ships, though, are either going to be very abstract, if you’re the captain giving orders, or over-zoomed in if one following orders. A partial way around it is to treat the ships as the characters for the fight. Easy for solo. Takes agency away from everyone but the captain in a group. Which is probably realistic, but hardly fun. Even so, you can have the gunner rolling for shots fired, navigator rolling dodge, etc.

I’ve been avoiding (solo) games with ship-to-ship combat, as much as I really want to, because I haven’t felt able to do it justice, yet. I suspect I’m going to end up somewhere between Pirate Borg and Worlds Without Number ship to ship combat, but playing as the ship, once I finally do bite the bullet.