First module of game/ai, and the first piece of Rung B that is not scaffolding. It is the two
halves of the AI's task selection that are pure: the 33-value task type enumeration and the
ranking that decides which goal the AI acts on first.
* the priority table, verbatim -- higher runs first, and it is the entire default policy;
* the five overrides, kept out of the table on purpose. The two artifact tasks ignore their
table entries (1 and 2) and return 1260/1261; a port that only copied the table would rank
them last instead of fourth and fifth. The two tuned invade priorities are INPUTS
(TaskPriorityPolicy), not constants, because their loader is not yet identified;
* Rank() as a stable descending sort. The original sorts a std::list, so stability is the
behaviour, not a choice -- ties keep creation order;
* CreationOrder(species, policyNonZero), because that is what breaks the ties. Four arms: the
NPC species builds nothing, Hiver is the only arm with the gate families, Zuul the only one
with NodeBore, everyone else shares a fourth. Both defensive families are gated on the
player's policy value and DefendGateIncoming is Hiver-only on top of that.
193 checks in tests/game_ai, every expected value read off the original's tables rather than
produced by running this code. ctest 46/46 -> 47/47; clean-room check OK.
Derivation: sots-re findings/subsystems/ai-task-system.md (lane AI2), sections 1-3.
