Migrates the 27 batches of type timesheets/fuel_logs/plant_hours out of
data_import_batches into the three document collections created in Task
6, preserving every source file and relinking every child row.
Status is derived from actual child count, not copied from the batch
row. Production proved the stored status cannot be trusted: every one of
these batches was written status=processed at creation time, before any
insert ran.
The bug is worse than the plan's own audit found. It predicted 18
phantom-processed batches, all plant_hours. Production has 21 -- three
timesheets batches are also phantom, including two byte-identical
re-uploads of the same wage sheet that both reported success and created
nothing. This hit payroll, not just plant-hour smoke tests.
Also: computed file_hash on migrated documents while the bytes were
already in hand (closes the same dedup gap Task 1 closed on delivery
notes and purchase orders), and split the schema-additive step
(--apply-fields) from the row migration (--apply) so the reversible part
can run independently of the irreversible one. The plan claimed
idempotency via a migrated_from_batch field that doesn't exist; replaced
with an explicit refuse-if-already-populated guard rather than pretend
resumability that isn't there.
27/27 migrated. 6/6 post-migration invariants verified: 3 fuel_sheets,
19 plant_hours_sheets, 5 timesheets, 1367/247/1 children relinked.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>