loading pet logs is sloooowwwwww, especially for long-time players

some possibilities (some may be mix/matchable; some may be mutually exclusive):
* any more indexing we can do? >_>
* delete many types of entries past a certain age (can lean on log "interestingness" score for this)
* archive all entries past a certain age - move them to some other storage mechanism
* utilize a dedicated search application (like Solr, but not Solr, because Solr sucks)
* we already have Redis... can that be leveraged?

No files, tests, or entry points are named. Start by locating and profiling pet-log loading for long-time players, then measure where time and storage are spent. Compare the proposed indexing, retention, archiving, and search options, and define acceptable loading time and data-retention behavior as the completion criteria.

Written by the indexing model from the issue text.