Liminalia citizen lineage and the kinship guard

liminalia

The relationship graph had a hole. RelationshipKind.Family existed but nothing ever assigned it, and nothing tracked parentage. Children were born with no link to their parents — so two siblings raised in the same household socialised, their affinity climbed past 80, ModifyAffinity promoted them to Partner, and PartnershipService formalised a household. An emergent bug, not a missing feature: the simulation was faithfully doing something nobody wanted.

lineage

Citizens now carry ParentA/ParentB, set at birth in PartnershipBirths. Founding citizens have none. IsKinOf covers parent and child in both directions plus full and half siblings (any shared parent) — null parents never match, so two founders socialising forever stay strangers.

the guard

RelationshipSystem gains an optional KinshipTest delegate the world installs in its constructor. ModifyAffinity consults it on every promotion: kin cap at Family where strangers would reach Friend or Partner. The system stays standalone — unit tests construct it bare, nobody is kin, existing behaviour unchanged. Births also register parent-child relationships as Family from the moment the child exists, before any socialising builds affinity.

save format v5

SaveCitizenData grows ParentA/ParentB strings; format 5 stores them. Format 4 and older load with null parents — those citizens are founders, and the guard treats them accordingly. Roundtrip tests confirm parentage, kinship recognition, and the promotion cap all survive a save/load cycle.

tests

KinshipTests: the sibling cohabitation regression (two siblings, affinity maxed, one tick — zero cohabitations), the promotion matrix (kin → Family, strangers → Partner, bare system → Partner), and birth lineage. LineageSaveTests: format 5 roundtrip and format 4 back-compat. 405 tests pass.