listExistingPeriodiseringsfonder still selected from journal_entry_lines
with a journal_entries!inner embed and put company_id/status/entry_date on
the embedded side: the shape PostgREST compiles to a correlated lateral
that scans all tenants' lines, and it silently truncated at the 1000-row
cap because it was unpaginated. Convert it to the shared two-step
fetchEntryLines helper (lib/bookkeeping/entry-lines.ts), mirroring
bolagsskatt-calculator.ts, and keep the existing wrapped error contract.
Adds unit coverage for listExistingPeriodiseringsfonder: helper call
shape, entry/line filter callbacks, per-account balance aggregation,
2129 cohort collision rule, 6-year must-return flag, near-zero drop,
sorting, and error wrapping.
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
