In a carousel snippet all carousel items keep a consistent height to prevent layout jitter when sliding. The height synchronization was broken in snippets like `s_image_gallery` or `s_carousel` when:
- An image was replaced with one of a different aspect ratio.
- Item dimensions were modified via border overlays (padding changes).

This commit introduces a `ResizeObserver` to monitor the carousel and triggers a height synchronization whenever an element's size changes.

Steps to reproduce (Media Change):
1. In the website builder, add the `s_image_gallery` snippet.
2. Replace one of its images with another which is significantly tall.
3. Navigate through the carousel and observe height changes causing a jitter effect.

Steps to reproduce (Border Overlay):
1. In the website builder, add the `s_carousel` snippet.
2. Drag the lower border overlay so that the height of an image increases.
3. Navigate through the carousel and observe height changes causing a jitter effect.

Task: [5135520](https://www.odoo.com/odoo/project/974/tasks/5135520)

When a mass mailing block uses a `bg-o-color-N` theme color class, the mailing's `body_arch` stores the class and `convert_inline` correctly inlines the resolved color into `body_html`, matching the website palette at save time. The class also stays on the element in `body_html`. The stylesheet rule that gives `bg-o-color-N` its color is declared with `!important`. When the website palette is later rebuilt (any change to the primary colors), the new `bg-o-color-N` rule wins over the inline color whenever `body_html` is rendered. So an already-sent mailing reopened in the backend shows the new palette's color instead of the one that was picked, and resaving the mailing bakes that new color into `body_html`.

`classToStyle` already does the right thing for the property value. What was missing is dropping the class itself from `body_html` once its style has been inlined, so no future `!important` palette rule can override the inline color. `body_arch` keeps the class, so the editor preview stays theme-aware while editing, but `body_html` is now stable across palette rebuilds.

Steps to reproduce:
1. Open Email Marketing and create a new mailing using the Welcome Message template
2. Select a content block, open Customize, set the background to the 5th theme color
3. Save the mailing
4. Open the Website editor and change the 5th primary color to a different value
5. Reopen the saved mailing in the backend

=> the block's rendered background follows the new website color instead of the one picked at design time

Ticket [link](https://www.odoo.com/odoo/project.task/5892350)
opw-5892350

**Steps to reproduce:**
1. Install l10n_es_edi_verifactu.
2. Switch to a ES company.
3. Create a customer invoice and send it to VeriFactu.
4. Enable Developer Mode.
5. Go to Settings > Technical > Sequences & Identifiers > Sequences.
6. Search for the `Sequence Code: l10n_es_edi_verifactu` and open it.
7. Set a prefix or suffix using any alphabetical character.
8. Create a new invoice and send it to VeriFactu

**Issue:**
Traceback on sending Veri*Factu:
`ValueError: invalid literal for int() with base 10: 'F260001'`

**Cause:**
The value returned by `ir.sequence.next_by_id()` may contain alphabetical characters (due to prefix/suffix), while the field `chain_index` expects an integer. The raw sequence value was directly assigned, causing the conversion to fail.

**Fix:**
Catch the ValueError raised by int() when the sequence value contains non-numeric characters (e.g. due to a prefix/suffix). Instead of crashing, surface a user-friendly error on the document telling the user to remove the prefix/suffix from the sequence configuration.

**opw-6037528**

**Issue:**
The printed receipt in Point of Sale displayed a negative change amount when the customer paid more than the order total.

**Before:**
The receipt showed the change as a negative value (e.g., `-$5,504.00`), which was misleading for customers.

**After:**
The receipt now correctly displays the change as a positive value (e.g., `$5,504.00`).

**Steps to Reproduce:**

1. Open a Point of Sale session
2. Add products to the cart (example total: `$49,496.00`)
3. Select the **Cash** payment method
4. Enter an amount greater than the order total (example: `$55,000.00`)
5. Observe that the **Change** field displays a negative value
6. Confirm the payment
7. Print the receipt and observe that the change amount is also negative

**Root Cause:**
The issue was caused by an unnecessary negation in the `export_for_printing()` method in `pos_order.js`.

The `get_change()` method already returns the correct positive change amount. However, the code applied an extra negation (`-this.get_change()`), which converted the value into a negative amount before rendering it on the receipt.

**Fix:**
Removed the unnecessary negation in `export_for_printing()` so the receipt now displays the correct positive change amount.

Video reproducing the issue: [[Click here to view the video](https://drive.google.com/file/d/1QnQ47qlTFvv98K0J_NzreBVeIh-J2XcF/view?usp=sharing)]

opw-6211988

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