🐞 Issue: `align: ""` is stripped, causing fallback to default align setting on load

[ouun]

Explicitly setting align: "" — such as when a user sets alignment to “none” — does not persist. It’s stripped during editor load, before saving, causing the block to fall back to its default alignment value (e.g. "full").

Steps to reproduce:

1. Define an ACF block via acf-composer with:

public $align = 'full';

public $supports = [
  'align' => true,
  // ...
];

2. Insert the block → it appears with align="full" ✅

3. Reset alignment to none in the editor → sets align: "" ✅

4. Reload the editor

5. Notice in editor markup that align is already removed → it was stripped on load

6. The block then renders with default align setting again, e.g. "full" ❌

Expected behavior:
ACF-composer should preserve explicit empty alignment attributes. If a user chooses no alignment, align: "" should persist through serialization and rendering, matching native blocks like core/cover.

What next:
This needs further testing & debugging (cached/uncached). A good starting point is here: https://github.com/Log1x/acf-composer/blob/master/src/Block.php#L391-L514