Stripe: reconcile the processor against the ledger

Constraints

1. 1Report only breaks. A reference that reconciles cleanly does not belong in an exception report.
2. 2status is one of 'amount_mismatch', 'missing_in_ledger' or 'missing_in_charges'.
3. 3A difference of 1 paisa or less — 0.01 — is rounding in transit, not a break. ORD-1002 differs by exactly that and must not be reported.
4. 4References that exist on only one side are breaks in both directions. ORD-1011 and ORD-1012 are in the ledger and were never charged.
5. 5charged and posted are NULL on whichever side has no row.
6. 6Order by status, then order_ref.

Worked example

ORD-1003 was charged 240.00 and posted 216.00 — a real break of 24.00. ORD-1005 was charged 310.00 and never posted. ORD-1011 was posted 42.00 and never charged. An inner join finds the first and neither of the others. A LEFT JOIN from the charges adds ORD-1005 and still cannot see ORD-1011 or ORD-1012, because nothing on the charge side points at them — 172.00 of unbacked ledger entries stay invisible. Comparing with c.amount <> l.amount adds the opposite error: it reports ORD-1002's one-paisa rounding as a break, and an exception report that cries wolf stops being read.

What this tests

Two-sided reconciliation: neither table is the driver, so the join has to preserve both sides, and equality on money needs a tolerance rather than an exact comparison.