Suggested character relations

Feedback:

>Characters with the same last name should be detected and suggested as relations.

This is a great idea; I'm not sure how to detect/guess at which relation they may be, but perhaps having something like a multiple-choice option for Serendipitous that asks "What is Alice Smith and Bob Smith's relation?" with a dropdown for father/daughter, mother/son, siblings, cousins, not related, etc.

For ambiguous answers (e.g. mother/daughter on two female characters), we can pull in other info (e.g. age) to guess which is which.

Would be fun to tackle. :)

The issue names no files, tests, or entry points to inspect. Begin by defining how same-surname characters should be detected, how relation choices and ambiguity are handled, and what acceptance criteria would demonstrate the completed feature.

Written by the indexing model from the issue text.