A* to a location and a given set of observations

[Zannick]

We had a best route with this segment:

494. Move to Annuna > Mirror Match > West Gap
495. ! Do Recall Drone
496. Move... to Uhrum > Annuna Corridor > Block East
497. Move... to Uhrum > Annuna Corridor > Block West ==
498. FastTravelKiengirwarp to Menu > Kiengir Map > Uhrum East

The item before this segment is collected as drone, and the item after this segment is collected as Indra; we need Indra later to take a specific Throw Drone edge. However, we can't improve this segment with our current A* helpers, because they go straight to the next item, which is certainly possible to get as drone, but then we can't perform that Throw Drone without spending even more time correcting our course. (I believe this segment was found before we added the Fast Travel point at Indra's location here, and then was never improved because we never processed another route that would match.

If we have the observation set from the subsequent item state, we could instead perform our A* search for a state that matches that observation, and thus not take any state that can't complete the rest of the route as-is.

One complication is that A* would work better if we can estimate how long it would take to change a differing observation to one that matches... But likely we should just use A* on the canon location and have a strict upper bound on time that's the original.