Add CLI push/pull for fonts
>>> [!note] Migrated issue
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<!-- Migrated from issue #3580221. -->
Reported by: [lauriii](https://www.drupal.org/user/1078742)
Related to !760
>>>
<h3 id="overview">Overview</h3>
<p>CLI cannot sync Brand Kit fonts; font config is editor-only, so CLI workflows cannot version or deploy fonts.</p>
<h3 id="proposed-resolution">Proposed resolution</h3>
<p>Introduce an optional <strong>canvas.brand-kit.json</strong> in the project root for font config (provider-based families via unifont or local <code>src</code> paths; variable fonts supported). When that file exists, <code>canvas push</code> resolves fonts, uploads them, and syncs the list to the global Brand Kit. When running <code>canvas pull</code>, changes fron the global Brand Kit are pulled to the code base.</p>
<h3 id="ui-changes">User interface changes</h3>
<p>None</p>
issue