fix(exchange-tx): notify Scrypt deposit only after bank_tx confirms money left

[davidleomay]

Summary

• Scrypt deposit requests were sent at bank payment transmission time, before the money actually arrived at Scrypt
• Scrypt created pending deposits that could take >24h to reconcile (changes ClReqID on completion)
• A cleanup cron marked them failed after 24h, racing against Scrypt's reconciliation
• This caused ~100k CHF double-count in the financial log (unmatched bank_tx in pending.toScrypt + same amount in live balance)

Fix

• Move the Scrypt deposit notification from the Yapeal/OlkyPay transmit step to searchOutgoingBankTx, where the matching bank_tx confirms the money left
• Remove the cleanupStalePendingDeposits cron — no longer needed since deposits won't be created prematurely

Root cause investigation

• Verified locally that Scrypt's fetchAll returns the completed deposit with Status: "Completed" but under a different ClReqID than the original pending record
• Confirmed by setting a failed deposit back to pending in prod — the sync picked it up and resolved to ok within one cycle
• The 24h cleanup was the only reason these deposits stayed failed

Test plan

• CI green
• After deploy: set remaining failed Scrypt deposits back to pending, verify they resolve to ok
• Monitor totalBalanceChf in financial log — should drop by ~100k CHF