Fix: Issue #732 - Viewer plays animation even when set to None

[crimson-and-clover]

This PR fixes an issue where the viewer still started a camera animation even when Animation = None was selected in the Publish panel.

Changes

• Add explicit 'none' option to startMode
• Prevent default animation fallback when startMode === 'none'
• Fix v1 → v2 migration to preserve startAnim: 'none'

Result

Viewer now correctly respects Animation = None and does not trigger any animation on load.

playcanvas/supersplat#732

[crimson-and-clover]

@slimbuck

[slimbuck]

Hi @crimson-and-clover,

Thanks for this PR!

We can't take this change right now because it will break existing published scenes that currently auto-animate.

We must first deal with the upstream publisher to add a new "do not animate" option before we can make this here change. So let's keep it around, shouldn't be long!

Thanks