- golem15.journal.related_mode (category | scored, default category) and
golem15.journal.related_count (3 to 6, default 3, clamped) in
config/config.yaml; classes.ReadRelatedSettings reads them
- the default mode answers GET /posts/{slug} exactly as before
- scored: related posts ranked by 2 points per shared tag plus 1 per
shared category, ties by newest, in one scoring query
(classes.ScoredRelatedPosts), published only for visitors; the answer
adds previous_in_category and next_in_category, the neighbours by
publish time within the post's first category by name
(classes.CategoryNeighbour), in the direction of previous_post and
next_post
- TestRelatedDefaultUnchanged, TestRelatedScored (a draft and a future
post sharing every tag never shown) and TestRelatedScoredCountClamped
