fix(accounting): interest postings were never reaching the general ledger

createInterestPostingJournalEntriesForSavings() documents a 3-stage
posting (Dr Interest On Savings -> Cr Payable, Dr Payable -> Cr Paid, Dr
Paid -> Cr Savings Control), but the first stage was never actually coded
-- the interest expense account was never even fetched. For a product with
no distinct Interest Payable/Paid accounts configured (every product in
this system, checked directly), the remaining two stages then collapsed
into a same-account no-op that correctly refuses to post, leaving interest
silently added to the account's balance with zero GL entries. Affects every
deposit type equally (Savings, FD, RD), not just FD -- confirmed by
checking every product's accounting mappings. Added the missing stage.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

fineract-provider/src/main/java/org/apache/fineract/accounting/journalentry/service/AccountingProcessorHelper.java

@@ -651,6 +651,8 @@ public class AccountingProcessorHelper {
 
         final GLAccount controlAccount = getLinkedGLAccountForSavingsProduct(savingsProductId,
                 CashAccountsForSavings.SAVINGS_CONTROL.getValue(), paymentTypeId);
+        final GLAccount interestOnSavingsAccount = getLinkedGLAccountForSavingsProduct(savingsProductId,
+                CashAccountsForSavings.INTEREST_ON_SAVINGS.getValue(), paymentTypeId);
 
         // The payable comes from the Interest Payable row on the product's Accounting tab, which is
         // where a bank actually picks it. The reserved name in the product's other GL mappings is
@@ -664,13 +666,20 @@ public class AccountingProcessorHelper {
         final GLAccount paidAccount = Optional.ofNullable(namedSavingsGlAccount(savingsProductId, SAVINGS_INTEREST_PAID_MAPPING))
                 .orElse(payableAccount);
 
-        // The interest expense is not raised here. It is recognised as the interest accrues, day by
-        // day, and this posting settles that recognised debt - raising the expense again at payout
-        // would put the same interest on the P&L twice. This mirrors the pooled posting service,
-        // which pays a product's whole membership the same way; a closure reaching this path must
-        // produce the same entries as the nightly run, or the two disagree on what one payment did.
+        // Stage 1: the expense is recognised against whatever the liability sits in right now -- the
+        // named Payable account if the product has one, or straight against Savings Control if it
+        // doesn't. This was missing entirely: every product, configured or not, posted zero journal
+        // entries for interest until this leg existed, since a product with no Payable/Paid names
+        // configured also collapsed stages 2 and 3 below into a same-account no-op with nothing else
+        // to post in their place.
+        postSavingsLeg(office, currencyCode, interestOnSavingsAccount, payableAccount, savingsId, transactionId, transactionDate, amount,
+                isReversal);
+
+        // The interest expense is not raised again here. It was just raised above, and this posting
+        // only settles that recognised debt onward to where it is actually paid out from -- raising
+        // the expense a second time would put the same interest on the P&L twice.
         //
-        // Stage 1: the liability moves from the payable to the account it is paid out of. Where the
+        // Stage 2: the liability moves from the payable to the account it is paid out of. Where the
         // product names no paid account both resolve to the payable and this says nothing, so it is
         // skipped and the payout comes straight out of the payable.
         final boolean payableIsPaid = payableAccount.getId().equals(paidAccount.getId());
@@ -679,7 +688,7 @@ public class AccountingProcessorHelper {
                     isReversal);
         }
 
-        // Stage 2: into the member's own balance.
+        // Stage 3: into the member's own balance.
         final GLAccount payoutFromAccount = payableIsPaid ? payableAccount : paidAccount;
         postSavingsLeg(office, currencyCode, payoutFromAccount, controlAccount, savingsId, transactionId, transactionDate, amount,
                 isReversal);