### Steps to reproduce:

**Issue 1:**
- Create a list with multiple items and leave the last item empty.
- Press Ctrl + A to select all content.
- Apply a text color from the toolbar.
- The list marker of the last item does not receive the color.

**Issue 2:**
- Create a list and type some text.
- Press Ctrl+A to select all.
- Apply a font size via the font-size input (inline style=`font-size: ...`).
- Then apply a font size via the font-size dropdown (class-based).
- Font size from the dropdown is not applied.

**Issue 3:**
- Create a list item and type some text.
- Convert the text into a link.
- Copy the link.
- Press Enter and paste the link.
- Select the entire list using the mouse.
- Apply font size & observe that font size is not applied to some list items.

**Issue 4:**
- Go to Todo and create a list.
- Select all items (Ctrl + A).
- Apply a background color class from the toolbar.
- Apply a font color using inline styling.
- Observe that the font color is not visible.

### Description of the issue/feature this PR addresses:

- Full-selection detection relied on Range.isPointInRange() checks on list item leaf nodes. When a list item ended with a trailing empty line, the selection often stopped on the `<li>` element and did not include the `<br>` placeholder. As a result, such list items were not considered fully selected when applying text color, and their markers remained unstyled.
- Applying a font-size class on a fully-selected list item could leave existing inline font-size on list item, so new class didn’t take effect.
- Creating links inside list items & repeated copy-paste operations left empty text nodes (feff cleanup). Manual selection doesn't include these nodes, `areNodeContentsFullySelected` reports that list item is not fully selected. As a result, some list items were not considered fully selected, and font size was not applied.
- Background color `(bg-*)` classes also define a color property. When a font color is applied, the color is set on the `<li>`, but the nested `font.bg-*` element’s color takes precedence, causing the applied font color to be overridden.

### Desired behavior after PR is merged:

- List items with trailing empty line are now treated as fully selected, even when selection ends before the `<br>` placeholder.
- Clear any existing font-size styles on the list item before applying the new font-size class, so the dropdown font size applies correctly.
- Empty text nodes are removed before applying font size, ensuring full list item selection and consistent font-size application.
- When a list item (li) has a text color (inline style or text-* class), and nested font element has only a background color class then font element now inherits the color from the li.

task - 5454639

Forward-Port-Of: odoo/odoo#241827

Steps to reproduce:
-------------------------------------
1. Install `hr_holidays_attendance` module
2. Time off > configurations > Time off types
3. Create new time off type as follows:
* Set Approval to Approved by time off officer
* Change Take time off In to Hours
4. Save the record and enable Deduct Extra Hours
5. Go to Management > Allocations
6. Create new allocation with created time off type and select 'Audrey Peterson' in Employee
7. Try to save record > Validation Error > Discard changes
8. Change time off type to Paid Time Off > add 'Audrey Peterson' > save record
9. Now change Time Off type to Created Time Off type > Save

Observation:
-------------------------------------
No Validation Error raised, as the employee and time off type are still the same as they were during creating allocation.

Issue:
-------------------------------------
In `write` method, there was no any check for the employee if it has enough overtime hours when we change Time off type (`holiday_status_id`) to overtime-deductible leave type.

Check was only present in the `create` method:
https://github.com/odoo/odoo/blob/a95c639db68f98351c7162de58a041a1c0ee13c5/addons/hr_holidays_attendance/models/hr_leave_allocation.py#L39-L49

Solution:
-------------------------------------
1. Create new function for validate overtime and to create adjustment
2. Added that function to `create` as well as in `write` method
3. Prevents creating a duplicate overtime adjustment for an allocation that already has one

opw-5937185

Forward-Port-Of: odoo/odoo#261529
Forward-Port-Of: odoo/odoo#249793