Build cross-system reconciliation cron

[Connorbelez]

Scope

Create cross-system reconciliation cron that detects gaps between transfers and downstream systems.

v2 Revision: Reconciliation Ownership Split (2026-03-22)

Ownership clarification: Reconciliation is jointly owned:

• Query implementations live in convex/payments/cashLedger/reconciliation.ts (Cash Ledger owns)
• Cron scheduling lives in convex/payments/transfers/reconciliation.ts (Payment Rails owns)

What to Build

In convex/payments/cashLedger/reconciliation.ts (extending existing module):

1. findOrphanedConfirmedTransfers() — Query transferRequests with status = "confirmed" older than 5 min, join against cash_ledger_journal_entries.transferRequestId. Missing entries → retry bridge effect → SUSPENSE after 3 failures.
2. findOrphanedReversedTransfers() — Same for status = "reversed" with missing REVERSAL journal entries.
3. findStaleOutboundTransfers() — Confirmed outbound transfers where linked dispersalEntry still pending.
4. findAmountMismatches() — Journal entries where amount ≠ linked transfer amount.

In convex/payments/transfers/reconciliation.ts (new file):

5. Cron registration: every 15 minutes, calls the above query functions and triggers self-healing.

Key Change from Original Scope

The reconciliation queries are NOT standalone — they extend the existing cashLedger/reconciliation.ts module which already has reconcileObligationSettlementProjectionInternal() and getControlBalancesByPostingGroup(). This ensures a single home for all financial reconciliation.

Dependencies

• ENG-199 (Cash Ledger Bridge — transferRequestId must exist on journal entries)

Acceptance Criteria

• Cron runs every 15 min without timeout
• Orphaned transfers detected within 5 min of confirmation
• Effect retry attempted before SUSPENSE escalation
• Reconciliation is idempotent
• Existing obligation-level reconciliation unaffected

[linear]

ENG-200