Replaces the previous "depth in generations along the strict
lineal chain" definition (which excluded siblings, aunts, cousins
entirely) with the metric the user actually wants: the number of
descent-steps separating the target from the recipient's closest
direct ancestor or descendant.
Examples relative to the recipient:
- sibling: 1 (parent → sibling)
- great-aunt: 1 (great-grandparent → great-aunt)
- nephew: 2 (parent → sibling → nephew)
- first cousin: 2 (grandparent → aunt → cousin)
- second cousin: 3
- ego, parents, grandparents, ..., children, ..., great-greats: 0
- own spouse, step-parents, brothers-in-law: inherit partner's
distance (so spouse-of-distance-1 is also distance 1)
Implementation:
- Anchor set seeded with R's direct ancestors + R + direct
descendants (capped at 25 generations to bound runaway data).
- Multi-source BFS expanding by descent only.
- Spouse propagation at every level so a person and their
spouse always share the same distance.
- Memoised per (recipient xref, max distance).
Tree preference key and range kept (NEWSLETTER_LINEAL_DEPTH,
0–10, default 3); only the semantics and the user-facing label
+ help text change, with concrete examples in both English and
German.
Alexander
105b09c4c5