### Issue
When importing an electronic bill (such as a German XRechnung) that uses the Peppol EAS 'EM' (Email) with an email address as the endpoint, the import fails during the automatic partner creation

An error is logged in the chatter stating that the Peppol endpoint is not valid and should contain only letters and digits

Since 'EM' stands for Email, the system should allow the '@' character and validate the endpoint format

### Cause
While the export logic supported the 'EM' EAS, the validation flow triggered during automatic partner creation on import was too restrictive

The global regex `PEPPOL_ENDPOINT_INVALIDCHARS_RE` did not include the '@' character, causing the
validation to fail for any email address

Additionally, there was no specific format check implemented for the 'EM' EAS type to ensure the endpoint is a valid email string

### Steps to reproduce
- Install `account_edi_ubl_cii`
- Go to Accounting / Vendors / Bills
- Upload an electronic invoice containing an EM EAS and an email endpoint (you can use the added test file or the one from the ticket)

Before the fix, an error is raised in the chatter and the partner cannot be created automatically

opw-6205745

Steps to reproduce:
1. Install CRM, Calendar, and Contacts.
2. Create a contact with an email address you can receive emails on.
3. Configure an outgoing email server.
4. Open a CRM lead and create a meeting activity using the calendar.
5. Add the created contact as an attendee of the meeting.
6. Return to the lead and click the Reschedule button on the activity.
7. Select the same meeting and change its start date to a future date.

Issue:
- Attendees receive the meeting date-change email twice.

Root cause:

- When a calendar event linked to an activity is rescheduled, the event write syncs the new start date to the related activity through `_sync_activities`. That activity write was not marked as calendar-originated after commit https://github.com/odoo/odoo/commit/bc090486bd7810b1b0af1bae398255a2d6615f09, so `mail.activity.write` treated the updated deadline as an activity-originated change and wrote back to the same calendar event.
https://github.com/odoo/odoo/blob/8cbb0fe91a35fcdb4a7e4e1a7e8afe40b1691f11/addons/calendar/models/calendar_event.py#L779
https://github.com/odoo/odoo/blob/8cbb0fe91a35fcdb4a7e4e1a7e8afe40b1691f11/addons/calendar/models/mail_activity.py#L24-L33
- This created a nested calendar event write. Both the nested write and the original write then triggered attendee date-change notifications, resulting in duplicate emails.

Solution:
- Pass the existing `calendar_event_meeting_update` context flag when syncing calendar event changes to linked activities. This prevents the activity sync from writing back to the event while preserving activity-to-event rescheduling.

opw-6209956

Currently, an error will occur when user multi edits name of projects.

Steps to replicate:
- Install `project` and open projects.
- From the list view select multiple projects and edit their name.

Error:
```
File '/home/odoo/src/odoo/saas-19.3/addons/project/models/project_project.py', line 754, in write
    analytic_account_to_update.write({'name': self.name})
File '/home/odoo/src/odoo/saas-19.3/odoo/orm/fields.py', line 1728, in __get__
    record.ensure_one()
File '/home/odoo/src/odoo/saas-19.3/odoo/orm/models.py', line 5341, in ensure_one
    raise ValueError('Expected singleton: %s' % self)
ValueError: Expected singleton: project.project(8, 9, 10)
```

Cause:
- As multiple records were changed at the moment, `self` had multiple recordsets and trying to access `self.name` [1] causes this error.

Solution:
- Avoided accessing `self.name` on a multi-recordset during multi-edit.
- Updated analytic account names using the name recieved in the vals.

[1]: https://github.com/odoo/odoo/blob/a69ec43f490735f639292d116b0207182c5b2581/addons/project/models/project_project.py#L608

sentry-7452096418
---
I confirm I have signed the CLA and read the PR guidelines at www.odoo.com/submit-pr

Forward-Port-Of: odoo/odoo#267620

Currently, an error will occur when user multi edits name of projects.

Steps to replicate:
- Install `documents_project` and open any project's settings using kebab menu (3 dots).
- Click new > name `Test` > open settings page and unselect `Documents` > Save.
- Click new > name `Test1` > Save.
- From the list view select `Test` and `Test1` and edit their name.

Error:
```
ValueError: Expected singleton: project.project(9, 10)
```

Cause:
- During `multi-edit`, self contains multiple project records.
- When only one of the selected projects has a documents folder (i.e. `use_documents` enabled), `self.documents_folder_id` contains that single folder, making `len(self.documents_folder_id.project_ids) == 1` to be True [1].
- The condition then proceeds to access `self.name` on the `multi-recordset`, raising singleton.

Solution:
- Avoided accessing `self.name` on a `multi-recordset` during multi-edit.
- Filtered projects individually and updated the document folders using the name in vals.

[1]: https://github.com/odoo/enterprise/blob/3c2985ca6011700c271ed14e40e08c89be822753/documents_project/models/project_project.py#L101

sentry-7452096418

Forward-Port-Of: odoo/enterprise#119060

Steps to reproduce
1. Configure a Polish company with KSeF enabled.
2. Create a customer invoice using a tax tagged with K_21 (0% EU G, intra-Community supply of goods), K_12 (0% EU S, services taxed in the buyer's EU country) or Triangular Sale.
3. Send the invoice to KSeF and download the generated FA(3) XML.

Issue
The Podmiot1 (seller) block in the rendered FA(3) XML omits the PrefiksPodatnika element, see https://github.com/odoo/odoo/blob/89219a843545d8bb0cad6ea806a1167cee6289da/addons/l10n_pl_edi/data/fa3_template.xml#L34-L42. According to the official Ministry of Finance documentation (https://ksef.podatki.gov.pl/media/4u1bmhx4/information-sheet-on-the-fa-3-logical-structure.pdf, page 11), this conditional field must carry the value "PL" when the invoice documents:
- the intra-Community supply of goods,
- the provision of services referred to in Article 100 sec. 1 item 1 of the Act for EU VAT taxpayers,
- the supply carried out under a simplified triangular transaction by the second taxpayer (Article 135 sec. 1 item 4 (b) and (c)). The XSD marks the element as optional (minOccurs="0", fixed="PL") so KSeF accepts the XML, but the seller's tax reporting is still legally non-compliant for the three cases above, and the field is missing from the KSeF PDF viewer rendering.

opw-6213178

Forward-Port-Of: odoo/odoo#264659

**Steps to reproduce:**
1. Install l10n_mx_hr_payroll.
2. Create an employee with a contract date over 35 years ago (e.g., 1985).
3. Create a payslip for this employee.
4. Click on "Compute Sheet".

```Error: KeyError(36) while evaluating```

**Cause:**
The rule parameter [rule_parameter_holiday_table](https://github.com/odoo/enterprise/blob/c02c4571bb7db7197b07539ba390d4d20fdce9fe/l10n_mx_hr_payroll/data/hr_rule_parameters_data.xml#L722-L758) defines values
only up to 35 years. Seniority exceeding this range causes a KeyError.

**Solution:**
Extended the `rule_parameter_holiday_2024` table from 35 to 60 years,
following the Mexican Federal Labor Law (LFT) reform formula
(+2 days every 5-year milestone from year 6 onwards).

**NOTE:**(Alternative approach)
```python
@staticmethod
def _get_mx_holiday_days(years_worked):
    if years_worked <= 0:
        return 0
    if years_worked <= 5:
        return 12 + (years_worked - 1) * 2
    five_year_periods = (years_worked - 6) // 5
    return 22 + five_year_periods * 2
    
  ```
This approach removes the need for XML data maintenance and handles
all future seniority values mathematically without any cap issues.
  
  
opw-6090590

Forward-Port-Of: odoo/enterprise#113536

Version:
----------
- 18.0+

Steps to reproduce:
-------------------
- Install `stock` module
- Enable `Storage Locations` from Inventory settings
- Create a tracked storable product with on-hand 8 units in `Shelf 1`
- Create Delivery 1 for 5 units and click `Mark as To Do`
- Create Delivery 2 for 5 units and click `Mark as To Do`
- Verify reservations:
  - Delivery 1 reserves 5 units
  - Delivery 2 reserves remaining 3 units
- Relocate all 8 units from `Shelf 1` to `Shelf 2` using the `Relocate` action from `stock quant`
- Reopen both deliveries

Issue:
------
After relocating stock between internal locations, reservations are reassigned
in the wrong order:
- Delivery 2 becomes fully reserved with 5 units
- Delivery 1 is reduced to 3 reserved units

This incorrectly swaps the original reservation priority between deliveries.

Cause:
------
The relocation wizard starts from:
`stock.quant.relocate.action_relocate_quants()`
which calls `move_quants()`:
https://github.com/odoo/odoo/blob/d3eebbd1c27e8a039bb55cdf2a82d464e06ffa8c/addons/stock/wizard/stock_quant_relocate.py#L70

`move_quants()` validates an internal stock move through `_action_done()`:
https://github.com/odoo/odoo/blob/d3eebbd1c27e8a039bb55cdf2a82d464e06ffa8c/addons/stock/models/stock_quant.py#L1572

During validation, `_synchronize_quant()` moves the stock quantity from
`Shelf 1` to `Shelf 2`.

However, the already reserved delivery move lines still reference `Shelf 1`.
This temporarily makes the source quant negative (`available_qty < 0`),
triggering `_free_reservation()`:
https://github.com/odoo/odoo/blob/d3eebbd1c27e8a039bb55cdf2a82d464e06ffa8c/addons/stock/models/stock_move_line.py#L695-L700

Inside `_free_reservation()`, move lines are ordered using
`current_picking_first`:
https://github.com/odoo/odoo/blob/d3eebbd1c27e8a039bb55cdf2a82d464e06ffa8c/addons/stock/models/stock_move_line.py#L816-L821

Since both deliveries share the same scheduled date, the fallback ordering
uses `-cand.id`, causing Delivery 2 (higher id) to be processed before
Delivery 1 (lower id).

The reservation cleanup therefore happens in this order:
- Remove Delivery 2 reservation (3 qty)
- Remove Delivery 1 reservation (5 qty)

The corresponding moves are then added to `move_to_reassign`
in the same order:
`[Delivery 2, Delivery 1]`
https://github.com/odoo/odoo/blob/d3eebbd1c27e8a039bb55cdf2a82d464e06ffa8c/addons/stock/models/stock_move_line.py#L849

Later, `move_to_reassign._action_assign()` processes the moves in recordset
order:
- Delivery 2 reserves 5 units first
- Delivery 1 only gets the remaining 3 units

As a result, reservation priority is unintentionally reversed after relocation.

Fix:
----
Before calling `_action_assign()`, reverse `move_to_reassign` 

This ensures reassignment preserves the original reservation order:
- Delivery 1 is reassigned first and recovers 5 units
- Delivery 2 receives the remaining 3 units

The reservation state therefore remains consistent before and after
internal stock relocation.

---

opw-6218256

---
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Forward-Port-Of: odoo/odoo#265169