Pre-implementation spec for the TTP-tagging worker. Defines the
ATT&CK-canonical vocabulary, schema (ttp_tag + ttp_rule[_state]),
bus topics, worker shape, lifter layering (rule-based v0,
behavioral/intel/email v0.5, sigma/biometric later), confidence
model, API surface, UI surface, observability, performance targets,
and a CDD plan (Appendix E) that splits contracts from tests with
xfail discipline so CI stays green between steps.