fix: remove KWH deposit workaround and deprecate currency-only helpers (#2119)

The financial-accounting posting layer now supports InstrumentAmount for
all asset types. Remove the seed script workaround that silently skipped
KWH deposits due to 'invalid currency' errors.

Mark ParseCurrency and CurrencyToInstrument as deprecated in favour of
InstrumentResolver.Resolve() which supports multi-asset instruments.

Co-authored-by: Ben Coombs <bjcoombs@users.noreply.github.com>

Author: bjcoombs

cmd/seed-dev/cmd/fixtures.go

@@ -388,25 +388,12 @@ func seedCustomerBalances(ctx context.Context, client currentaccountv1.CurrentAc
 
 		// KWH meter read deposit - CREDIT customer kWh account, DEBIT GSP inventory account.
 		// Uses InstrumentAmount (input field) for non-monetary instruments.
-		// NOTE: financial-accounting currently only supports ISO-4217 currencies,
-		// so KWH deposits fail at the posting layer with InvalidArgument. Skip
-		// that specific error gracefully; propagate unexpected errors (network, auth).
 		if err := depositInstrumentIdempotent(ctx, client, acct.kwhAccountID, dailyKWH, "KWH",
 			fmt.Sprintf("Meter read %s: %.2f kWh", date.Format("2006-01-02"), dailyKWH),
 			fmt.Sprintf("METER-%s-%s", acct.partyID, date.Format("20060102")),
 			acct.gspKwhAccountID, // GSP inventory account is the debit (clearing) side
 		); err != nil {
-			// The saga wraps the financial-accounting rejection as Internal, and the
-			// inner error is InvalidArgument with "invalid currency". Match on the
-			// error message to avoid masking unrelated Internal errors.
-			errMsg := err.Error()
-			if strings.Contains(errMsg, "invalid currency") || strings.Contains(errMsg, "invalid posting_amount") {
-				if day == 30 {
-					fmt.Printf("  [WARN] KWH deposits skipped for %s (financial-accounting does not yet support non-monetary instruments)\n", acct.customerName)
-				}
-			} else {
-				return fmt.Errorf("deposit KWH for %s day %d: %w", acct.customerName, day, err)
-			}
+			return fmt.Errorf("deposit KWH for %s day %d: %w", acct.customerName, day, err)
 		}
 	}
 

services/financial-accounting/domain/currency.go

@@ -39,6 +39,10 @@ func ParseCurrency(s string) (Currency, error) {
 //   - Precision: derived from the currency's decimal places (e.g., 2 for GBP, 0 for JPY)
 //
 // Returns an error if the currency is invalid.
+//
+// Deprecated: Use InstrumentResolver.Resolve() for all new code.
+// This function only supports ISO 4217 currencies. For multi-asset support,
+// resolve instrument properties from Reference Data via InstrumentResolver.
 func CurrencyToInstrument(c Currency) (Instrument, error) {
 	if !c.IsValid() {
 		return Instrument{}, ErrInvalidDimension

shared/domain/money/money.go

@@ -79,7 +79,9 @@ func (c Currency) DecimalPlaces() int32 {
 
 // ParseCurrency converts a string to a Currency type with validation.
 //
-// Deprecated: Use shared/pkg/refdata.InstrumentResolver.Resolve() instead.
+// Deprecated: Use InstrumentResolver.Resolve() for all new code.
+// This function only supports ISO 4217 currencies. For multi-asset support,
+// resolve instrument properties from Reference Data via InstrumentResolver.
 func ParseCurrency(s string) (Currency, error) {
 	c := Currency(s)
 	if !c.IsValid() {