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>