Improe model viewer logic in product gallery, add support for control buttons

[alvinkonda]

Summary

Improve model viewer behavior in the product gallery and add support for control buttons.

Scope

• Refine product gallery model-viewer loading/render logic.
• Add configurable control buttons for model interactions.
• Ensure behavior is consistent with other media types in the gallery.

Acceptance Criteria

• Model viewer loads reliably in product gallery.
• Control buttons are visible and functional.
• No regressions for image/video/iframe gallery items.