Fix keyboard events dropped after selecting sprite in UI

[Chessing234]

Summary

• Forward keydown events to the VM unless the event target is a text input, textarea, or contentEditable element
• Replaces the previous check that dropped keys for any non-document/SVG target, which caused key-sensing blocks (e.g. "when space key pressed") to stop working after clicking a sprite in the sprite selector

Fixes the same root cause reported in scratchfoundation/scratch-gui#10047 (that repo is archived; this monorepo is the active home for scratch-gui).

Test plan

• Add a "when space key pressed" block and confirm space still triggers it after clicking a sprite in the sprite list
• Confirm Blockly number/text field inputs still accept typing without forwarding keys to the VM
• Run npm test -- --testPathPattern=vm-listener-hoc in packages/scratch-gui

Made with Cursor

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