Drop Fomantic tab, checkbox and form patches (#37377)

Clean up the fomantic helpers that nothing inside fomantic depends on.
Manually tested all functionality.

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Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

web_src/js/features/imagediff.ts

@@ -1,7 +1,6 @@
 import {GET} from '../modules/fetch.ts';
 import {hideElem, loadElem, queryElemChildren, queryElems} from '../utils/dom.ts';
 import {parseDom} from '../utils.ts';
-import {fomanticQuery} from '../modules/fomantic/base.ts';
 
 type ImageContext = {
   imageBefore: HTMLImageElement | undefined,
@@ -101,8 +100,6 @@ class ImageDiff {
     this.containerEl = containerEl;
     containerEl.setAttribute('data-image-diff-loaded', 'true');
 
-    fomanticQuery(containerEl).find('.ui.menu.tabular .item').tab();
-
     // the container may be hidden by "viewed" checkbox, so use the parent's width for reference
     this.diffContainerWidth = Math.max(containerEl.closest('.diff-file-box')!.clientWidth - 300, 100);