web.page-catalog: level-wise page hierarchy/fluxogram

[EmoonX]

Organize pages in a similar vein as how level progress is dictated by the level_requirements table. In other words, establish a hierarchical structure in a "page Y depends on page X being reached first" basis.

To ease a great deal of the work, in riddles with enough playerbase, access_time among several players could be used as a reliable heuristic to extract a topological ordering, and thus an initial structure ready for later review/fine-tuning.

Overall, this would reinforce and elucidate the hierarchical structure of how pages are arranged in levels, and also serve as a pseudo-walkthrough on how to progress through each one.