phsl / new-api

Ensure the header logo is shown only after the image has fully loaded to eliminate flicker:

• Introduced `logoLoaded` state to track image load completion.
• Pre-loaded the logo using `new Image()` inside a `useEffect` hook and set state on `onload`.
• Replaced the previous Skeleton wrapper with a stacked layout:
  – A `Skeleton.Image` placeholder is rendered while the logo is loading.
  – The real `<img>` element fades in with an opacity transition once both global
    `isLoading` and `logoLoaded` are true.
• Added automatic reset of `logoLoaded` whenever the logo source changes.
• Removed redundant `onLoad` on the `<img>` tag to avoid double triggers.
• Ensured placeholder and image sizes match via absolute positioning to prevent layout shift.

This delivers a smoother visual experience by keeping the skeleton visible until the logo is completely ready and then revealing it seamlessly.