Something incredible, something impossible, something that people have thought of doing but never had the guts/time/will/dwarves to complete.
Make an unmodded, fully-featured fort run by dwarves (and clockwork, possibly including immortal goblin timing treadmills). One part of your score is the number of keystrokes (human or scripted) required per dwarf year; lowest is best. To count as "fully featured" you need to not merely survive, but defeat, at least two sieges without human (or script, utility, etc.) input; in other words a fully automatic means to detect, defeat, clean up, reset, and be ready again for the next one that can run over and over again. Significant bonus points for defeating a FB or titan with minimal keystrokes. There should be no particular reason why the fort couldn't last 10, 100, or even 1,000 years; everything irrevocably consumed after the first few years of setup should be infinitely renewable (this includes dwarves, making sure that you're not loosing dwarves faster than they breed, or conversely outbreeding your food & booze production).
It seems like most if not all of the technical parts to do this have been created in one thread or another, but to my knowledge no one has actually done this. I suspect that the state of the art would still require minimal intervention to handle unexpected events; you will need to either make very sure FBs cannot get to the "working" parts of the fort or have a way of handling them.
Interesting variant, which may be more relevant as we get to more of the caravan arc: You have possessed the broker. Once the initial setup phase is past, you are not allowed any interactions with the fortress except those personally performed by the broker, who can have no other jobs enabled. This allows full use of the trading interface, and possibly pulling a few key levers (all levers must be set to the broker only) in emergencies. You may only pass on your "gift" to direct blood descendants of the starting broker, and only on death.
Inspiration: Various people I follow were involved in the
100 Year Starship Study, which was intended to ask a number of hard questions about what we are lacking in humanity's toolbox to deal with long-term plans on this scale. There are some obvious similarities to DF's shortcomings in terms of required external intervention.
For those familiar with the
Angband Borg, there are some interesting related thoughts; one implication of a minimal-keystrokes-required fort is that those keystrokes could be supplied by an AI script. As computers become more powerful, running an AI DF in the background (possibly coming to the front as a screensaver during otherwise idle time) becomes more practical. Aside from the interesting AI challenges, this would be a great way to created worlds to adventure in; let the AI play a half-dozen forts for a few decades (or centuries) each without peeking, and then you'd truly have a world full of unknown wonders and horrors to face as an adventurer.