Accountant-entered QuickBooks reconciliation snapshots and their parity with Median (#2873)

For a client whose books are on QuickBooks, returns per bank or card account the current accountant-entered QuickBooks snapshot (reconciled-through date and ending balance, who recorded it and when), Median's latest completed reconciliation of that account (statement ending date and statement ending balance), and the parity between the two. Median does not read these values from QuickBooks and never writes them there: the snapshot is a person's statement. The comparison is between two recorded figures; it does not re-read the ledger, so a journal posted into the reconciled window after Median's completion is not detected here. Parity is derived at read time and never stored, in this order: not_verified when no snapshot exists, when Median has no completed reconciliation, when the snapshot is stale, when Median's reconciliation is not clean (its difference is not exactly 0, or it was force-completed, including a quick-complete within a tolerance), or when the currencies differ; behind when QuickBooks is reconciled through an earlier date, ahead when later; on the same date agree when the balances are equal and balance_differs when not. Tolerance is 0: cents are compared exactly. balanceComparison says how: signed compares the values as stored; magnitude, used for credit-card accounts only, compares absolute values, because QuickBooks shows a card balance as a positive amount owed while Median's reconciliations store it with either sign. Staleness rule (no day count): a snapshot is stale when Median completed a reconciliation of that account after the snapshot was recorded. Without bankAccountId the list holds every business bank or card account of the client. A snapshot whose bank account was later deleted is kept as history and is not listed. When the company has no QuickBooks ledger connection the answer is applicable: false with an empty list. Read-only.