Fix "The sidebar of the repository file list does not have a fixed height #34298"

[kerwin612]

There is a known issue where scrolling to the bottom of the page is affected by unknown elements in the footer area:

gitea/templates/base/footer.tmpl

Lines 11 to 18 in 24145f8

	{{template "custom/body_outer_post" .}}
	{{template "base/footer_content" .}}
	<script src="{{AssetUrlPrefix}}/js/index.js?v={{AssetVersion}}" onerror="alert('Failed to load asset files from ' + this.src + '. Please make sure the asset files can be accessed.')"></script>
	{{template "custom/footer" .}}

[kerwin612]

The aforementioned issue can be resolved by inserting the following code in the initRepoViewFileTree function within web_src/js/features/repo-view-file-tree.ts:

  // TODO: the parent element's full height doesn't work well now,
  // but we can not pollute the global style at the moment, only fix the height problem for pages with this component
  const parentFullHeight = document.querySelector<HTMLElement>('body > div.full.height');
  if (parentFullHeight) parentFullHeight.style.paddingBottom = '0';

  window.addEventListener('scroll', () => {
    const contentBottom = repoViewContent.getBoundingClientRect().bottom;
    if (contentBottom <= sidebar.offsetHeight) {
      sidebar.style.paddingTop = `${sidebar.offsetHeight - contentBottom}px`;
    } else {
      sidebar.style.paddingTop = '0';
    }
  });

However, I refrained from directly submitting this solution due to potential performance concerns and its lack of elegance. The current page structure constraints make it challenging to devise alternative approaches. Does anyone have suggestions or alternative solutions?