# Payment ledger reconciliation

Internal demonstration by Clorvin Labs. This is a small engineering exercise, not a client engagement or a measurement of model performance.

Implement `reconcile(entries)` in Python. Each entry has string fields `id`, `account` and `amount`. An amount must have two decimal places, no exponent or leading zeroes, and may be negative. Whitespace-only fields are invalid.

Return account balances sorted by account name, the overall total, and a count of unique entries. Amounts in the output must be strings with exactly two decimal places. Do not use floating-point arithmetic. Repeated IDs with the same account and numeric amount count once. Conflicting repeated IDs raise ValueError. Invalid or missing fields also raise ValueError. Reordering the input must not change the report.

Run: `python verify.py`. To check another implementation: `python verify.py path/to/candidate.py`.

The public checks cover cents, refunds, duplicate IDs, conflicts, all permutations of a three-entry ledger, malformed amounts, missing fields, empty input, large values and cancellation. They are finite checks, not a proof of correctness for every input.

No network or external packages are needed. Docker is optional; its base image tag is not digest-pinned. This exercise does not claim any financial compliance or suitability as an accounting system.