Issue:
-------
After the fix:
https://github.com/odoo/odoo/commit/f1557211d9e7f83761bb36e4800e4c2f62b234c5 we can't create a child menu for a mega menu or a menu can't be a mega menu when there's an existing child menu except the case of top level menu i.e; (url: /default-main-menu) and that menu will have no parent_id obviously...

Now, as per the above pr conditions the top level can be set as mega menu since it has no parent id. And in version 17.3 in the pr https://github.com/odoo/odoo/commit/47af533e9f5f721b63570d3b301951f3855384a1 a 'Jobs' menu is being created and its parent_id refers to that top level menu which we have set as mega menu. And when the records gets validated during migration the database will get blocked.

Solution:
-----------
Restrict the user by throwing the same user error, when checking/selecting the top level menu as mega menu since it has existing child menus.

Step to reproduce:
-----------------------
1. Create a database in version 17.0 with 'website_hr_recruitment' installed.
2. Go to website menus, set a top level menu(/default-main-menu) as mega menu.
3. Migrate the database to version 18.0 or more.

Traceback:
```
File "/home/odoo/src/odoo/18.0/odoo/models.py", line 5297, in _create
    records._validate_fields(name for data in data_list for name in data['stored'])
  File "/home/odoo/src/odoo/18.0/odoo/models.py", line 1636, in _validate_fields
    check(self)
  File "/home/odoo/src/odoo/18.0/addons/website/models/website_menu.py", line 95, in _validate_parent_menu
    raise UserError(_("A mega menu cannot have a parent or child menu."))
odoo.exceptions.UserError: A mega menu cannot have a parent or child menu.

 File "/home/odoo/src/odoo/18.0/odoo/tools/convert.py", line 603, in _tag_root
    raise ParseError('while parsing %s:%s, somewhere inside\n%s' % (
odoo.tools.convert.ParseError: while parsing /home/odoo/src/odoo/18.0/addons/website_hr_recruitment/data/config_data.xml:13, somewhere inside
<record id="website_menu_jobs" model="website.menu">
            <field name="name">Jobs</field>
            <field name="url">/jobs</field>
            <field name="parent_id" ref="website.main_menu"/>
            <field name="sequence">59</field>
        </record>
```

Ref Images:
Before Fix:
<img width="1598" height="599" alt="image" src="https://github.com/user-attachments/assets/ef719945-a11b-4134-97f8-4b583c4ea6bc" />

After Fix:
<img width="1582" height="633" alt="image" src="https://github.com/user-attachments/assets/da326e45-0de8-4d42-ad47-845bfaedc84e" />


OPW - 6094298


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

Forward-Port-Of: odoo/odoo#280458
Forward-Port-Of: odoo/odoo#263025

Opening a tax report from a return and submitting it could act on a different
return than the one on screen.

_get_return_from_report_options searches by company, period and report with
limit=1, but that combination is not unique: l10n_nl declares two return types
on l10n_nl.tax_report, nl_tax_return_type and nl_tax_correction_return_type, so
a VAT return and its correction both match. Which one is returned is then
decided by _order (is_completed, date_deadline, name, id).

For a Dutch VAT correction it resolves to the original VAT return of the same
quarter, so send_xbrl submits and flags that record instead of the correction.

The options already carry the return type they were built for, in the
return_periodicity filter, so restrict the search to it when it is set.
l10n_nl_reports kept a return_id option for the same reason when computing the
already declared amount of a suppletie; it can use
_get_return_from_report_options now.

opw-6421300

Forward-Port-Of: odoo/enterprise#129278
Forward-Port-Of: odoo/enterprise#127073

### Issue:
When moves share the same `sequence_number` in a journal but have different suffixes (e.g. `INV/2026/00010` and `INV/2026/00010A`), the `made_sequence_gap` flag was incorrectly set

### Cause:
`_update_sequence_made_gap`, introduced in commit https://github.com/odoo/odoo/commit/17893089e8b21c0ecab5e61ed8e2c33f3731b3ac selects the previous and next moves ordered by `sequence_number` without filtering by suffix

This causes two issues:
- Moves from different suffix sequences are used as neighbors, leading to incorrect gap detection
- Duplicate `sequence_number` values across suffixes are not accounted for, so only one move is considered per number

### Steps to reproduce:
- Install `account`
- Post 12 invoices to get a sequence up to `INV/2026/00012`
- Reset `INV/2026/00012` to draft, rename it to `INV/2026/00010A`
- Reset `INV/2026/00010A` to draft, rename it to `INV/2026/00009A` and confirm
Before the fix: `INV/2026/00011` is red
Expected: `INV/2026/00011` should not be red because `INV/2026/00010` exists
- Delete `INV/2026/00009`
Before the fix: `INV/2026/00010` is red
Expected: `INV/2026/00010` should be red (gap in no-suffix sequence)
- Reset `INV/2026/00009A` to draft and confirm it again
Before the fix: `INV/2026/00010` is not red
Expected: `INV/2026/00010` should still be red (different suffix)

### Notes:
Suffix changes are treated as distinct sequences following the same gap rules as any other sequence
This was agreed with R&D — the gap flag is meant to signal inconsistencies within a sequence, not across suffixes

opw-6454823

Forward-Port-Of: odoo/odoo#282503

### Before this fix
---

The `_get_so_mapping_from_project()` method returns a mapping where the key is
the move line ID and the value is a `sale.order` record (or `None`).

Because of the issues described below, a valid `sale.order` could be available
for reinvoicing, but the corresponding move line might still not be mapped to
that sale order. As a result, the move line is not added to the reinvoiceable
sale order.

However, the implementation has two issues:

#### 1. Projects are overwritten when they share the same analytic account

`project_per_accounts` is built as a dictionary mapping an analytic account ID
to a single project. If multiple projects reference the same analytic account,
each new assignment replaces the previous one. As a result, only the last
project associated with a given analytic account is retained.

**Example:**

* Analytic Account **AA1** is linked to **Project A** and **Project B**.
* The dictionary becomes `{AA1: Project B}`.
* **Project A** is lost, even though it also references **AA1**.

**Steps to reproduce:**

1. Create an analytic account **AA1**.
2. Create **Project A** and **Project B**, both linked to **AA1**.
3. Create **Sale Order SO1** linked only to **Project A**.
4. Create a vendor bill (or expense) that generates an AML using **AA1** for a
   product configured with **Reinvoice Costs = At Sales Price**.
5. Validate the document.

**Expected behavior:**
The product should be added to **SO1** for reinvoicing.

**Actual behavior:**
The move line is not mapped to **SO1**, so no sale order line is created.

#### 2. Previously found projects are overwritten during iteration

The `project` variable is reassigned on every iteration of the loop. After the
loop completes, it only contains the project (or lack of one) corresponding to
the last processed analytic account. This can cause valid projects found earlier
in the loop to be discarded.

**Example:**

* Move line has analytic accounts **AA1** and **AA2**.
* **AA1** maps to **Project A**.
* **AA2** has no linked project.
* After the loop, `project` is `None`, even though **Project A** was found.

**Steps to reproduce:**

1. Create analytic accounts **AA1** and **AA2**.
2. Create **Project A** linked to **AA1** only.
3. Create **Sale Order SO1** linked to **Project A**.
4. Create a vendor bill (or expense) whose AML is distributed between **AA1**
   and **AA2**, where **AA2** is processed after **AA1**.
5. Validate the document.

**Expected behavior:**
The move line should still be mapped to **SO1** because **AA1** references
**Project A**.

**Actual behavior:**
The last processed analytic account (**AA2**) overwrites the previously found
project, causing the move line not to be linked to **SO1**.

### After this fix
---

* `project_per_accounts` stores **all** projects associated with each analytic
  account instead of keeping only the last one.
* The project lookup preserves all valid project candidates instead of
  overwriting previously found results during iteration.
* As a result, the method can resolve the related `sale.order` in more cases,
  improving the overall accuracy of the mapping.

> **Note:** This change prevents valid project associations from being lost
> when multiple projects share an analytic account or when multiple analytic
> accounts are processed for the same move line.

**OPW:** 6294615

Forward-Port-Of: odoo/odoo#277110

**Steps to reproduce:**
- Install Accounting and l10n_se
- Switch to a Swedish company (e.g. SE Company)

- In Accounting settings, set "Identification" with anything
- In Bank journal:
  * Set an account number
  * Make sure "Swedish ISO20022" is available in "Outgoing Payments"
  * Set "pain.001.001.09" as "XML Format" in "Outgoing Payments"
- Create a vendor payment:
  * Vendor: [a vendor with a trusted bank account]
  * Payment Method: Swedish ISO20022
  * Amount: [any]
- Confirm the payment
- From the payments list, select the payment and create a batch
- Validate the batch payment

**Issue:**
When the batch is validated, a `pain.001.001.09` file should be generated. However, its content is that of a `pain.001.001.03` file, even if the version reported in the file is `pain.001.001.09`.

For example, `<ReqdExctnDt>` should contains a subnode `<Dt>` in `001.001.09`, which is not the case.

It leads to the file being rejected as non-compliant to `pain.001.001.09`.

opw-6472050

Forward-Port-Of: odoo/enterprise#129506
Forward-Port-Of: odoo/enterprise#128598