[samchinmaya]

Description

Jira: FINERACT-2994

With accrual (periodic) accounting on a savings product, SavingsAccount.deposit() and withdraw() call accrualsForSavingsReverse(), which reverses the accruals dated on or after the new transaction so the accrual job books them again from the new balance. The undo methods (undoTransaction(Long), undoSavingsTransaction(Long), undoTransaction(SavingsAccountTransaction)) only reversed the transaction itself. The accrual job only adds accruals after the last one, so accruals on money that was no longer there stayed in Interest Payable and Interest Expense.

This PR moves the reversal loop into reverseAccrualsFrom(date, backdatedTxnsAllowedTill) (used by accrualsForSavingsReverse() as before) and calls it from the three undo methods with the undone transaction's date (not when the undone transaction is itself an accrual). undoTransaction in SavingsAccountWritePlatformServiceJpaRepositoryImpl already collects the reversed transactions before and after and posts their journal entry reversals, so the reversed accruals get reversal entries.

Tests: new SavingsAccountUndoTransactionAccrualTest (2 tests): undoing a deposit reverses the accruals on and after its date and keeps the earlier one, with the normal and the pivot-date transaction lists. Both fail on the old code; the fineract-savings domain tests pass.

Manual check on a jibBuildTar image of this branch vs apache/fineract:0df2ef786f (develop), PostgreSQL. Savings product with accounting rule 3, 6% nominal annual interest; accounts activated 01 July 2026; "Add Accrual Transactions For Savings" run after each step:

Case	develop: payable after undo → after next job	this PR	expected
Deposit 5000, undo the deposit (balance 0)	96.80 → 96.80	0.00 → 0.00	0.00
Deposit 10000, withdraw 4000 on 01 Aug, undo the withdrawal	136.53 → 136.53	50.84 → 193.54	193.54 (account with the same 10000 and no withdrawal)

Savings control GL = account balance and balanced entries in every step, before and after.

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