Pre-target phases (RECONNAISSANCE/RESOURCE_DEVELOPMENT/WEAPONIZATION/
SOCIAL_ENGINEERING) and observable-but-unmappable phases (EXPLOITATION/
PIVOTING/OBJECTIVES, UKC-only concepts ATT&CK lacks tactics for) are
pinned as lossy via _LOSSY_INVERSE_REFERENCE so a future contributor
cannot 'fix' the asymmetry without tripping the suite.