This fixes an issue where contract signing plans still referenced an outdated employee field after plans were updated to support multiple employees. The change helps ensure the right employees are included when using HR contract signing workflows.

odoo/enterprise#24728 made plans available for multiple employees, but
odoo/enterprise#25511 still used the old field name.

This fixes how exchange rate dates from the Turkish bank are read by using the correct month-first date format. It helps ensure currency rates are imported for the right dates, reducing accounting and reporting errors.

Users can now open the related records from pivot header formulas in Documents spreadsheets without encountering an error. This fixes a crash and makes spreadsheet analysis more reliable.

Before this commit, trying to open the records on a PIVOT.HEADER formula
caused a traceback.

Task-id 2833129

This update fixes minor code quality issues flagged by automated checks across several Odoo Enterprise modules. It helps keep the software easier to maintain and reduces the risk of small internal errors, without introducing visible functional changes for users.

COM PR: https://github.com/odoo/odoo/pull/86332