This update establishes a connection between employee records within the HR Payroll module. This linked list functionality improves data consistency and simplifies payroll processing by maintaining relationships between employees. It's an important improvement for accurate payroll calculations.

This commit adds two helper fields to form a linked list between employee records.

task-6159337

This update fixes a technical issue in the Gantt view that prevented users from correctly filtering work orders when grouping by work centers. The fix ensures consistent functionality and prevents errors related to incorrect data interpretation, improving the overall planning process.

Before this commit:
-------------------------
- When planning work orders in the Gantt view, applying a Group By on Work
  Center and then adding another grouping (e.g., Manufacturing Order or
  Status) caused a traceback when clicking grouped rows in the panel.

Steps to reproduce:
-------------------------
1. Install the `mrp_workorder` module.
2. Create and plan a Manufacturing Order.
3. Open the Planning Gantt view
4. Apply Group By → Work Center.
5. Add another group by (e.g., Manufacturing Order or Status)
6. Click on one of the groups (MO or Status) in the side panel.

Cause of the issue:
-------------------------
- Rows grouped by Work Center -> Manufacturing Order attempted to access
  a Work Center record that does not exist, leading to the error:
  `TypeError: Cannot read properties of undefined (reading 'display_name')`
- Rows grouped by Work Center -> Status incorrectly treated the status
  value as a Work Center ID, leading to the error:
  `psycopg2.errors.InvalidTextRepresentation: invalid input syntax for type integer`

After this commit:
-----------------------
- Rows created directly from the Work Center grouping are now correctly
  linked using their corresponding `workcenterIds` and remain clickable.
- Rows created by additional groupings after Work Center (e.g.,
  Manufacturing Order or Status) are no longer clickable.
- This ensures a consistent interaction flow in the Gantt view and prevents the
  previous errors during filtering.

Task ID: 6132396

Forward-Port-Of: odoo/enterprise#114565

This update fixes an issue where WhatsApp channel avatars were incorrectly displaying the default Discuss avatar after a member was added. Now, avatars are correctly pulled from the channel's WhatsApp member, ensuring accurate representation and a better user experience for WhatsApp channel communication. This improves the visual consistency and reliability of the WhatsApp sidebar.

WhatsApp sidebar avatars should be resolved from the channel's whatsapp member, not from an arbitrary non-self member.

Before this fix,
adding a member to a WhatsApp channel caused the default Discuss avatar to be displayed instead of the actual WhatsApp member's avatar. This happened because the correspondent was not correctly computed for channels of type whatsapp.

task-[5879840](https://www.odoo.com/odoo/project/1519/tasks/5879840)

Forward-Port-Of: odoo/enterprise#118012
Forward-Port-Of: odoo/enterprise#115745

A test was failing related to employee departures within the ESG HR module. This change corrected the test by ensuring that departures are only processed for employees with active contracts, aligning with business requirements. This resolves a technical issue preventing accurate reporting.

This test was failing due to the new changes at https://github.com/odoo/odoo/pull/264906
Departures can not be on an employee without a contract, hence the change from employee 3 (without a contract) to employee 1 (with a contract) in the test.

task-6223154

This update resolves an issue preventing employers from correctly managing multiple MPF accounts linked to the same registration number. The change relaxes a previous restriction, allowing valid multi-account configurations while still ensuring uniqueness based on the combination of registration and account numbers. This improves data accuracy for Hong Kong payroll.

An employer can legitimately hold multiple employer account numbers under the same MPF registration number. The previous constraint rejected any two MPF schemes sharing the same registration number, blocking valid multi-account configurations.

Fix the validation to only restrict the duplicate based on the combination of registration number and employer account number.

task-6232561

Forward-Port-Of: odoo/enterprise#118109