Feature cross-reference (SST/UST/IST/EST) and feature->filesystem
mapping for the planned cross-file Services editor. Reconciliation
exact: 160 feature rows, every service number exactly once.
Flags for review: UST list is 4 short of the spec (147-150 missing
from EF_UST_SERVICES), GSM Access gates DF.GSM-ACCESS 5F3B (not DF.GSM),
CCP/CCP2/ECCP equivalence, and three unresolved file mappings.
