Salary offers can now include a contract end date. When an offer is accepted and the employee contract is created, that end date is automatically applied, reducing manual follow-up and improving contract accuracy.

this commit added contract end date in offer, If the offer contract end date is set, then the created contract will have the end date field populated

task- 4853216

Payroll payment reports now use the clearer label “payment date,” and payslips are automatically updated with that date. US payslip layouts are simplified to show the payment date, hide less relevant employee details, and display only the last four digits of bank accounts for clearer employee communication.

When creating a payment report, the user must can choose the effective date. The term is ambiguous and is replaced by this commit by payment date. Additonnaly, the pay_date field on the payslip is automatically filled according to the payment date of the attached payment report.

Also, this PR improves the US payslip template to better follow best practices:
- The payment date is added
- The job position, department and worked days are hidden
- The phrasing of the bottom sentence has been changed and only the last four digits of the bank account are shown

task-4814800

Australian payroll rule parameters have been updated for the 2025 period. This helps ensure payroll calculations use the latest applicable values, supporting accurate payslips and compliance for Australian employees.

Forward-Port-Of: odoo/enterprise#88323

Appointment sharing links are now generated in one consistent place, reducing duplicate behavior across calendar, form, Kanban, and Gantt flows. Users get cleaner name-based links when possible, fewer duplicate invites, and more reliable link editing and creation.

Purpose:
The short_code generation mechanism is made central, such that Kanban, Form, and Gantt views' share invite's code duplication can be avoided.

Specifications:
1. Generate a unique link. 
   Case 1: Generate name based link when no link exists for the appointment eg. /schedule-a-demo. 
   Case 2: If a link exists for the appointment: Retrieve the existing link for the current configuration, or else generate a random code.
2. Avoid invite duplication on appointment duplication.
3. Change the button string from Cancel to Discard and short_code_unique_warning in view appointment_invite_view_form.
4. Remove AppointmentInviteViewFormController and associated files, as the same code is done on the server side to avoid code duplication.
5. Generate an appointment name-based link(if the link does not exist)for the appointment listed in the dropdown on the calendar side.
6. We can now alter the short_code of existing link and generate a new link.
7. Set default appointment type when we click on New btn in list view of links of the appointment.
8. Update the appointment name which is created via 'Share Calendar' click.
9. Test case has been created so above functional flow doesn't break.

Task-4610207

Co-authored-by: Aurélien awa@odoo.com

Belgian payroll now places the ONSS CO2 fee before the employer ONSS contribution and includes it in that employer contribution total. This helps ensure payslip calculations and reporting better reflect the required treatment of company car CO2 fees.

The ONSS CO2 Fee must appear before the ONSS employer rule and included in its sum.

task-3506696

The Partner Ledger no longer shows debit and credit amounts on initial balance and total lines. This reduces confusion from large historical amounts that do not relate directly to the selected reporting period.

Users are sometimes confused because Debit and Credit can show quite high amounts not related to the present period because of the initial balance.
We hide these columns for the initial balances, and to remain consistent, for the totals as well in the partner ledger.

taskid: 4261294