fix: screen-reader fixes for day highlights button and chips toggle

The Highlights button's aria-label overrode its content, so the visible
"· analysed" suffix was never announced — the analysed state is now
mirrored into the label (at render and when a highlights run completes).
The chips toggle's accessible text started with a stray space (left over
once the aria-hidden arrow is dropped), which read as an indent; the
separator space now lives inside the aria-hidden arrow span.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

webui.html

@@ -765,7 +765,7 @@ function renderFiles(files) {
       </h2>
       ${canHl ? `<button class="day-hl" id="dayhln-${dayId}"
         aria-expanded="false" aria-controls="dayhl-${dayId}"
-        aria-label="Day highlights for ${esc(day)}">
+        aria-label="Day highlights for ${esc(day)}${analysed ? ', analysed' : ''}">
         <span class="day-arrow" aria-hidden="true">▸</span> Highlights<span
           class="day-hl-status" id="dayhls-${dayId}"${analysed ? '' : ' hidden'}> · analysed</span></button>` : ''}`;
     section.appendChild(headBar);
@@ -1046,16 +1046,18 @@ async function dayHighlights(dayId, analyzableFiles) {
       const arrow = document.createElement('span');
       arrow.className = 'day-arrow';
       arrow.setAttribute('aria-hidden', 'true');
-      arrow.textContent = '▸';
+      // the separator space lives inside the aria-hidden arrow: a leading
+      // space in the text node shows up as an indent in screen readers
+      arrow.textContent = '▸ ';
       tog.appendChild(arrow);
       tog.appendChild(document.createTextNode(truncated
-        ? ` Top ${chipList.length} sections by loudness`
-        : ` ${chipList.length} sections`));
+        ? `Top ${chipList.length} sections by loudness`
+        : `${chipList.length} sections`));
       tog.addEventListener('click', () => {
         const exp = chips.hidden;
         chips.hidden = !exp;
         tog.setAttribute('aria-expanded', exp);
-        arrow.textContent = exp ? '▾' : '▸';
+        arrow.textContent = exp ? '▾ ' : '▸ ';
       });
       box.appendChild(tog);
     }
@@ -1067,8 +1069,13 @@ async function dayHighlights(dayId, analyzableFiles) {
   hlRow.dataset.loaded = hlParams();
   dayHlSections.set(dayId, dayActiveSections);
   // Every file is now cached with the current params
-  if (results.length === n)
+  if (results.length === n) {
     document.getElementById('dayhls-' + dayId)?.removeAttribute('hidden');
+    // aria-label overrides the button content, so the analysed marker has to
+    // be mirrored into it or screen readers never hear it
+    if (btn && !/, analysed$/.test(btn.getAttribute('aria-label') || ''))
+      btn.setAttribute('aria-label', btn.getAttribute('aria-label') + ', analysed');
+  }
   if (btn) btn.disabled = false;
 }