fix: ignore deferred panzoom transforms after the preview image is gone - #4216

Description

Closing or leaving an image in the preview right after it appears no longer throws a setStyle error, because a late zoom/pan update from the removed image is now ignored.

Related Issue

• Fixes Preview logs a setStyle error when an image is left right after it appears #4199

How Has This Been Tested?

• test environment: unit tests (Vitest), browser tests (Playwright) against a local OpenCloud
• test case 1: unit: a deferred setTransform after unmount doesn't throw
• test case 2: browser: closing or switching right as the image appears (desktop and Pixel 7), zoom, rotate, reset and keyboard navigation unchanged

Types of changes

• Bugfix
• Enhancement (a change that doesn't break existing code or deployments)
• Breaking change (a modification that affects current functionality)
• Technical debt (addressing code that needs refactoring or improvements)
• Tests (adding or improving tests)
• Documentation (updates or additions to documentation)
• Maintenance (like dependency updates or tooling adjustments)