Improve linear compatibility with Safari, run button metadata (#8107)

I downloaded the oldest webkit based browser I could find after reports
of display issues. The changes here cause some minor styling tweaks, but
should be more compatible overall. A quick list of fixed issues
- Center panel placeholder had incorrect aspect ratio
<img height="500" alt="image"
src="https://github.com/user-attachments/assets/b75e3c49-20d9-4d6e-bca4-95cc8a73f821"
/>
- Image previews had incorrect aspect ratio (But the other way around)
<img height="500" alt="image"
src="https://github.com/user-attachments/assets/b8ebc58e-2655-41f8-a3b4-70ba65940612"
/>
- On mobile, output groups would flex incorrectly, resulting in a large
gap between them
<img height="500" alt="image"
src="https://github.com/user-attachments/assets/ed7e8e43-c34e-4ffc-a3ee-126b1a2ef4e0"
/>



Also moves the run button trigger source to a new 'linear' type


┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8107-Improve-linear-compatibility-with-Safari-run-button-metadata-2ea6d73d3650814e89cbc190b6ca8f87)
by [Unito](https://www.unito.io)

src/components/ui/ZoomPane.vue

@@ -47,7 +47,7 @@ const transform = computed(() => {
 <template>
   <div
     ref="zoomPane"
-    class="contain-size flex place-content-center"
+    class="contain-size place-content-center"
     @wheel="handleWheel"
     @pointerdown.prevent="handleDown"
     @pointermove="handleMove"