monetr: Protected Transactions Deletable via PUT

monetr is a budgeting application focused on planning for recurring expenses. Prior to 1.12.3, a transaction integrity flaw allows an authenticated tenant user to soft-delete synced non-manual transactions through the transaction update endpoint, despite the application explicitly blocking deletion of those transactions via the normal DELETE path. This bypass undermines the intended protection for imported transaction records and allows protected transactions to be hidden from normal views. This vulnerability is fixed in 1.12.3.