Each column already leads a composite UNIQUE constraint whose btree covers
leftmost-prefix lookups on it (and the ON DELETE CASCADE reverse lookups),
so the extra single-column index=True was pure write-amplification. Drop
index=True on the 10 columns + alembic 0062 drops the existing indexes
(DROP INDEX IF EXISTS; downgrade recreates). Verified: migration up/down
round-trips on localdev (10 indexes drop, composites intact), siftlode
check green (alembic upgrade head incl. 0062 + pytest 193). The 10 do not
appear in an alembic-check model/DB diff → models and migration agree.
peter
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