v0 Phase 1 of ATTRIBUTION-ENGINE.md:
* AttributionStateRow SQLModel keyed on (identity_uuid, primitive)
per ANTI direction — re-keying state rows when the v1 clusterer
merges attackers is the migration debt v0 should not bake in.
ATTRIBUTION-ENGINE.md updated with the deviation note.
* AttributionMixin: ensure_stub_identity_for_attacker, idempotent
upsert_attribution_state, get_attribution_state[_for_identity],
list_multi_actor_identities (the Phase 5 correlator's read).
* attribution.profile.{state_changed,multi_actor_suspected} bus
topics + builder; wiki Service-Bus.md updated separately.
* attribution_worker.py: subscribes to attacker.observation.>,
ensures stub identity per event, logs and continues. No merger,
no state writes, no derived events — Phase 4 wires those.
* attribution/{aggregate.py,_thresholds.py} skeletons: Phase 2
fills _aggregate_categorical, Phase 3 adds numeric+hash+dispatcher.