Release 2026w32

Improved periodic-billing invoice dates and fixes for deleted-entry timers, invoice presentation and validation, backdated billing, and employee email changes.

• ↻ChangedBilling (MK2-8119): Newly created periodic billing schedules use the schedule run date for draft invoices, while existing schedules retain month-end invoice dates.
• ✓FixedTime (MK2-7931): Deleting a timed work item stops its timer instead of leaving an orphaned timer running.
• ✓FixedBilling (MK2-8375): The AU But Say invoice summary includes non-fee categories such as Discounts on separate lines with the correct amounts.
• ✓FixedBilling (MK2-8387): Retained invoice amounts are validated against the gross total rather than the net total; this fix was also included in 2026w31.
• ✓FixedBilling (MK2-8388): Backdated invoices can be created through the new invoice date-filtering screens; this fix was also included in 2026w31.
• ✓FixedBilling (MK2-8399): Filter by Date Range defaults to off during invoice creation; this fix was also included in 2026w31.
• ✓FixedBilling (MK2-8400): Invoice Editor currency formatting is consistent, including pound symbols for UK tenants; this fix was also included in 2026w31.
• ✓FixedBilling (MK2-8404): The Scheduler and Invoice Editor consistently use the label Bill by Date Range; this fix was also included in 2026w31.
• ✓FixedSystem (MK2-8338): Employee and contact email changes validate the linked user account and block updates that would desynchronise the record and login identity.