[Feature Request] evaluate Steps Stats and Recommended (re)learning steps per preset

[FraserLee]

is your feature request related to a problem? Please describe.

If you have multiple decks sharing a preset, it's currently not possible to see the Steps Stats window over all the cards in that present. Users can only see it for one deck, or over the entire collection.

Describe the solution you'd like

Either

• (worse) move the step-stats from the old statistics page to the new page, where users can manually filter down to a preset using the search window at the top with preset:<name>, or
• (better) move recommended (re)learning steps into the preset options view, so a user can set the (re)learning steps to optimal values for the preset directly, or
• (best, probably a lot of work) integrate optimal (re)learning steps with the new sub-day FSRS scheduling to fully automate the entire system, without any manual user intervention in choosing step sizes at any point in the process.

Describe alternatives you've considered

It's possible to manually compute this statistic by cloning the profile, deleting all decks that don't have the desired preset, linearising the graph structure (might not be necessary?), then viewing step stats for the entire collection. Pretty labour intensive, but it'd get you there.

[L-M-Sherlock]

It's hard to switch to preset-level because the old stats pages is in deck-level. PR is welcome.