feat: territory as strategy — expansion decree, living borders, reachable ages

Territory is a choice, not physics. New decree('expansion', 0-1000,
default 500): the base camp footprint is automatic, but all reach beyond
it — tier, age, and population (+1 claim budget per 25 of isqrt(pop),
capped) — is scaled by the decree. Isolationists stay deliberately small;
manifest destiny claims every acre and borders keep creeping as the
civilization grows, so the territory chart no longer flatlines at tier 3.

Ages were unreachable in practice: age 1 needs 100 hides, hides come from
herd slaughter, and the founding herds were culled at the first slow tick
for lack of pasture. The hall now shelters a small founding flock (6 herd
+ 2 herder slots), and the reference bots manage herds with hysteresis
(slaughter fat flocks, spare thin ones), build pastures with pop, and
express territorial identity through the expansion dial.

Docs updated (decree table, territory-as-choice section, pasture note);
goldens repinned; test harness opts into full expansion explicitly.

commit

d5920e46d0a04c5f311abc8da289de4f73077ff1

parent

7e8e1f813443346dd0091d102622be90fb2416d7

author

Dami <dami.etoile@gmail.com>