Replace Fomantic search module with first-party autocomplete

Drops the 1565-line vendored Fomantic UI search jQuery plugin in favor
of a small first-party TypeScript module covering the three call sites
(repo, user, and team autocomplete). Adds an e2e regression suite that
exercises each search box.

Also fixes input/button vertical alignment in the four forms that wrap
a search box: the fomantic-era `tw-align-middle` workaround is replaced
by `flex-text-block` on the form, which is the codebase's standard
flex helper for this layout.

Co-Authored-By: Claude (Opus 4.7) <noreply@anthropic.com>

web_src/js/features/comp/SearchRepoBox.ts

@@ -1,4 +1,4 @@
-import {fomanticQuery} from '../../modules/fomantic/base.ts';
+import {initSearchBox} from '../../modules/fomantic/search.ts';
 import {htmlEscape} from '../../utils/html.ts';
 
 const {appSubUrl} = window.config;
@@ -10,22 +10,17 @@ export function initCompSearchRepoBox(el: HTMLElement) {
   if (exclusive === 'true') {
     url += `&exclusive=true`;
   }
-  fomanticQuery(el).search({
-    minCharacters: 2,
-    apiSettings: {
-      url,
-      onResponse(response: any) {
-        const items = [];
-        for (const item of response.data) {
-          items.push({
-            title: htmlEscape(item.repository.full_name.split('/')[1]),
-            description: htmlEscape(item.repository.full_name),
-          });
-        }
-        return {results: items};
-      },
+  initSearchBox(el, {
+    apiUrl: url,
+    onResponse(response: any) {
+      const items = [];
+      for (const item of response.data) {
+        items.push({
+          title: htmlEscape(item.repository.full_name.split('/')[1]),
+          description: htmlEscape(item.repository.full_name),
+        });
+      }
+      return {results: items};
     },
-    searchFields: ['full_name'],
-    showNoResults: false,
   });
 }