This commit aligns the Italian e-invoicing (FatturaPA) generation for One Stop Shop (OSS) transactions with the requirements of the Italian Revenue Agency ( Agenzia delle Entrate).

Current behavior:
Invoices for intra-EU B2C sales (OSS) are generated with a single line containing the foreign VAT rate. This is rejected or considered non-compliant by the SDI because foreign VAT cannot be typically exposed in the standard way for Italian electronic invoices.

New behavior:
The XML generation logic has been updated to follow the specific codification required for OSS operations:

1. Invoice Lines (`DettaglioLinee`):
   - The product line is reported with 0% VAT and Nature 'N7' (VAT paid in another EU member state).
   - A new, separate line is injected to represent the VAT amount, classified with Nature 'N2.2' (Non-taxable/Other).

2. Tax Summary (`DatiRiepilogo`):
   - The original foreign tax lines are excluded from the summary.
   - Synthetic summary lines are added for the 'N7' (Taxable Base) and 'N2.2' (VAT Amount) categories.

Implementation details:
- Added `_l10n_it_is_oss_tax` helper to identify OSS taxes.
- Modified `_l10n_it_edi_get_line_values` to split OSS lines.
- Modified `_l10n_it_edi_get_tax_values` to adjust the tax summary.

task-4711509

Description of the issue/feature this PR addresses:

Current behavior before PR:

Desired behavior after PR is merged:




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

Forward-Port-Of: odoo/odoo#249243
Forward-Port-Of: odoo/odoo#243740

### Contains the following commits:

https://github.com/odoo/o-spreadsheet/commit/decaa468c5 [REL] 18.2.43 [Task: 0](https://www.odoo.com/odoo/2328/tasks/0)
https://github.com/odoo/o-spreadsheet/commit/4295869a84 [FIX] dynamic_tables: trim overlap on the correct side [Task: 5905900](https://www.odoo.com/odoo/2328/tasks/5905900)
https://github.com/odoo/o-spreadsheet/commit/9d985b705d [FIX] Evaluation: Provide cell position on single formula evaluation [Task: 5798610](https://www.odoo.com/odoo/2328/tasks/5798610)

Co-authored-by: Florian Damhaut (flda) <flda@odoo.com>
Co-authored-by: Anthony Hendrickx (anhe) <anhe@odoo.com>
Co-authored-by: Alexis Lacroix (laa) <laa@odoo.com>
Co-authored-by: Lucas Lefèvre (lul) <lul@odoo.com>
Co-authored-by: Adrien Minne (adrm) <adrm@odoo.com>
Co-authored-by: Ronak Mukeshbhai Bharadiya (rmbh) <rmbh@odoo.com>
Co-authored-by: Dhrutik Patel (dhrp) <dhrp@odoo.com>
Co-authored-by: Rémi Rahir (rar) <rar@odoo.com>
Co-authored-by: Pierre Rousseau (pro) <pro@odoo.com>
Co-authored-by: Vincent Schippefilt (vsc) <vsc@odoo.com>
Co-authored-by: Marceline Thomas (matho) <matho@odoo.com>

When opening an SO in POS that has a product tracked by lot that is split into several location, the lot number will only appear in one of the line and not the others

Steps to reproduce:
-------------------
1. Create a Product A tracked by lot, create lot 111 and add 1 unit to location A and another one to location B
1. Create a sales order
2. Add two units of the product to the sale order
3. Confirm the sales order
4. Open the transfer, make the transfer retrieve the product from several location with the same lot.
5. Save the transfer
6. Open the sales order in POS
7. Load the SN/lots
-> Two line of qty 1 appear for the product A but only the first one has the lot number

Additional Issue:
8. Change the number of the product for the first line to 2 and erase the second line
9. Confirm and Pay
10. Close POS
11. Open move lines for this product (Inventory>product>In/out)
-> It moves 2 product from one location (when there is only product)

Observation:
-------------
When loading the SO in POS, we will retrieve the SO: https://github.com/odoo/odoo/blob/cb1f5d9c6db64b9ace9b7aa46bd6f94e4462176b/addons/pos_sale/static/src/app/order_management_screen/sale_order_management_screen/sale_order_management_screen.js#L104 While retrieving the SO, we will also retrieve the SOL, with additional information: https://github.com/odoo/odoo/blob/d9b2e5ee730a4e79586bfd3f09adfb794d2dc1f3/addons/pos_sale/models/sale_order.py#L79 -> Issue is that when several moves_line have the sale lot_id.name, their quantity will be overwritten.

Addition Issue :
When closing pos, all the move will be processed, when processing those moves, the origin only check if the quantity is more than 0 and not if there is enought units. https://github.com/odoo/odoo/blob/cb1f5d9c6db64b9ace9b7aa46bd6f94e4462176b/addons/point_of_sale/models/stock_picking.py#L293-L297

opw-5347992

Forward-Port-Of: odoo/odoo#250196
Forward-Port-Of: odoo/odoo#243347

### Issue:
When an employee has a flexible calendar, its gantt view in planning and other modules, like project or time off, shows incorrect grayed-out days. In general, employees with a flexible calendar should not have any grayed out days other than public holidays.

### Steps to reproduce:
- Create a new work schedule:
    - Flexible Hours
    - 24 hours per week
    - 8 average hours per day
- Create an employee with this work schedule
- Open Planning app
- Only the three first days of the week are not grayed out

### Cause:
With 24 hours per week, the worked time can be done in three days. Odoo considers that the first three days of the given time frame are worked, but the others aren't. This result is returned by `_work_intervals_batch()`. In `_unavailable_intervals_batch()` we then build the unavailabilities by taking the inverse of the work intervals. The only exception was for fully flexible resources (i.e. without a calendar).

### Solution:
The case we need to consider is for flexible resources: they are available anytime, all week long except on public holidays and leaves.

To do this we fix the method `_unavailable_intervals_batch()` which is then called by each module. If the resource is flexible, then we only return the interval of the public holidays overlapping with the time frame.

Works in `appointment`, `hr_holiday_gantt`and `project_enterprise`.

In `planning`, we need to skip the case where nothing is returned in `leaves_mapping` otherwise it will consider the `company_leaves` during weeks with no public holiday or leaves.

In `hr_attendances_gantt`, `_unavailable_intervals_batch()` is not called. So we change the way the unavailabilities were computed to call `_unavailable_intervals_batch()` instead.


opw-4879481

Forward-Port-Of: odoo/odoo#245741

In certain conditions all lines in invoice require a tax. When making
a down payment from an order containing products using fixed price tax,
the corresponding invoice line was created without tax. The issue appear
both when making the down payment from the sale order and from the PoS.

Steps to reproduce:
-------------------
* Create a fixed price tax of 10€
* Create a product with this tax
* Create a sale order with this product and make a downpayment of 10%
> Observation: The down payment line has no tax set.
* Open PoS and make a down payment of 10% for the same order
* Pay and invoice the order
> Observation: The down payment line has no tax set.

Why the fix:
------------
If the tax is required on every invoice line we manually add a 0% tax to
the down payment line to ensure that the invoice is compliant.

At the moment we only add the tax when peppol is activated on the
current company. But the `_require_tax_ids_on_invoice_lines` method can
be overriden by other modules if downpayment lines also require tax.

opw-5853070

Forward-Port-Of: odoo/odoo#247748

### Issue:
When an employee has a flexible calendar, its gantt view in planning and other modules, like project or time off, shows incorrect grayed-out days. In general, employees with a flexible calendar should not have any grayed out days other than public holidays.

### Steps to reproduce:
- Create a new work schedule:
    - Flexible Hours
    - 24 hours per week
    - 8 average hours per day
- Create an employee with this work schedule
- Open Planning app
- Only the three first days of the week are not grayed out

### Cause:
With 24 hours per week, the worked time can be done in three days. Odoo considers that the first three days of the given time frame are worked, but the others aren't. This result is returned by `_work_intervals_batch()`. In `_unavailable_intervals_batch()` we then build the unavailabilities by taking the inverse of the work intervals. The only exception was for fully flexible resources (i.e. without a calendar).

### Solution:
The case we need to consider is for flexible resources: they are available anytime, all week long except on public holidays and leaves.

To do this we fix the method `_unavailable_intervals_batch()` which is then called by each module. If the resource is flexible, then we only return the interval of the public holidays overlapping with the time frame.

Works in `appointment`, `hr_holiday_gantt`and `project_enterprise`.

In `planning`, we need to skip the case where nothing is returned in `leaves_mapping` otherwise it will consider the `company_leaves` during weeks with no public holiday or leaves.

In `hr_attendances_gantt`, `_unavailable_intervals_batch()` is not called. So we change the way the unavailabilities were computed to call `_unavailable_intervals_batch()` instead.

Forward-Port-Of: odoo/enterprise#105521

Issue:
Sending PUE payments to CFDI/SAT is no more suitable

Step to reproduce:
- In a Mexican company
- Create an invoice (Invoice A)
- Add a line
- Set Payment Terms to "Immediate payment"
- Confirm
- Duplicate (Invoice B)
- Confirm
- Duplicate again (Invoice C)
- Set Payment Terms to "30 days"
- Confirm
- Go to Invoice A
- Pay it. It should appear as "Paid"
- Send it to CFDI
- Go to Accounting > Customer > Invoices
- Select Invoice B and C
- Pay and select the "Group Payments". They should appear as paid.
- In every invoice, click the "Update Payment" button

Current behavior:
- In Invoice A -> Sheet CFDI: A button "Force CFDI" allow sending the payment to CFDI
- In Invoice B/C -> sheet CFDI: Click on the "Download" part of the Payment line, the XML that was sent to CFDI include both invoice B and C

Expected behavior:
- It shouldn't be possible to send payment for invoice A to CFDI.
- Payment for invoice B shouldn't be sent to CFDI

Cause:
Payment for invoice paid in less than 30 days, referred as PUE, shouldn't be sent to CFDI.

Solution:
Disable the force sending to CFDI

About tests:
l10n_mx_edi_cfdi_invoice_try_update_payments already send payment to CFDI for PPD invoices. Calling action_force_payment_cfdi was pointless and causing a mess.

opw-5381600

Forward-Port-Of: odoo/enterprise#108932
Forward-Port-Of: odoo/enterprise#104628

### Issue:
The pill name contains the hours when it spans over the next day for less than 3 hours but not if more than 3 hours.

### Steps to reproduce:
- Go to Planning app
- Create a shift for an employee from 3pm to 2am (over two days)
- The hours of the shift are displayed
- Modify the shift end to 3am
- The hours of the shift aren't displayed

### Cause:
Before the refactor adapting the gantt view to OWL, when a shift spanned over two days less than three hours, then the gantt view truncated the pill to display it in only one day. (see [`_snapToGrid()`](https://github.com/odoo/enterprise/blame/a16b2ef569903c0ae5803c169dbd68acd0141fe1/web_gantt/static/src/js/gantt_row.js#L1044-L1072)) The same logic was done for the computation of the pill's name in [this commit](https://github.com/odoo/enterprise/commit/98a86cbacf484646f486e4648788cfa53cc9648c).

But as the pills are no longer truncated since 17.0, the computation of pill names is faulty.

### Solution:
We remove the checks of the 3-hour margin. This also makes the variable `spanMoreThanOneDay` useless, so we delete it.

opw-5881532

Forward-Port-Of: odoo/enterprise#108897
Forward-Port-Of: odoo/enterprise#107233