fix(suggest): the dropdown reopened on top of the search results

Three staging-gate failures, two of them one real bug.

After a search, the results-page bar still holds the term in its input,
so on every render the query was >= 2 characters and the suggestion list
opened again — on top of the very results the search had just produced.
Playwright reported it as "<li role=option ...> intercepts pointer
events" while trying to click the first result; a reader would simply
have found their first result unclickable. Both the school-detail and
hero-map journeys failed on it, and neither is about autosuggest.

Suggestions now answer typing, not the mere presence of a value:
`hasTyped` gates the hook, is set on change, and is cleared when a
search is submitted or a suggestion is chosen. A pre-filled input makes
no request and shows no list.

Third failure was my test, not the product. An unphased place page
renders one table per phase, and an all-through school legitimately
appears in both — so the page's school links were never one alphabetical
run. The assertion collected them all together and only passed because
no town it picked had held an all-through school. When the data gave
Abbots Langley one, Breakspeare School appeared in the primary table and
again in the secondary, and the test failed on correct behaviour. It now
checks each table separately, and passes against the data that broke it.

Guards: a jest test that a pre-filled input neither fetches nor opens
(verified by reverting — it is the only one that fails), and an E2E
journey that submits a search and then requires the first result to be
clickable, which is the reader-facing version of the same thing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015mWQnpye9F299NVRCCSRvj

nextjs-app/components/FilterBar.tsx

@@ -69,14 +69,28 @@ export function FilterBar({
   const [omniValue, setOmniValue] = useState(initialOmniValue);
 
   const suggestId = `school-suggest-${isHero ? "hero" : "bar"}`;
+
+  /*
+   * Suggestions answer typing, not the mere presence of a value.
+   *
+   * Without this the results-page bar reopened the dropdown over the results:
+   * after a search the input still holds the term, so on every render the
+   * query was >= 2 characters and the list opened again — on top of the very
+   * results the search had just produced, swallowing the click on the first
+   * one. The E2E gate caught it as "<li role=option> intercepts pointer
+   * events", but a reader would just have found the page unclickable.
+   */
+  const [hasTyped, setHasTyped] = useState(false);
+
   // Suppressed once the value parses as a postcode: the box takes a school
   // name OR a postcode, and suggesting schools during postcode entry fights
   // the user rather than helping them.
-  const suggestEnabled = autosuggest && !isValidPostcode(omniValue);
+  const suggestEnabled = autosuggest && hasTyped && !isValidPostcode(omniValue);
   const { suggestions, open, activeIndex, setActiveIndex, close } =
     useSchoolSuggest(omniValue, suggestEnabled);
 
   const pickSuggestion = (s: Suggestion) => {
+    setHasTyped(false);
     close();
     track('search_submitted', {
       query: s.school_name.toLowerCase(),
@@ -169,6 +183,9 @@ export function FilterBar({
 
   const handleSearchSubmit = (e: React.FormEvent) => {
     e.preventDefault();
+    // The search has been made; the suggestions that led to it are spent.
+    setHasTyped(false);
+    close();
     if (!omniValue.trim()) {
       updateURL({ search: "", postcode: "", radius: "" });
       return;
@@ -271,7 +288,7 @@ export function FilterBar({
             ref={inputRef}
             type="search"
             value={omniValue}
-            onChange={(e) => setOmniValue(e.target.value)}
+            onChange={(e) => { setOmniValue(e.target.value); setHasTyped(true); }}
             onKeyDown={handleOmniKeyDown}
             onBlur={close}
             placeholder="School name or postcode"