Sort keywords column: matched entries first, then unmatched, both alphabetical

When filters are active, viable (matched) keywords now appear at the top
of the Mots-clés column so users don't have to scroll past faded entries
to find clickable tags. Both groups maintain alphabetical order internally.

app/templates/partials/repertoire-index.php

@@ -111,6 +111,12 @@ foreach ($filterColumns as $col) {
 <div id="repertoire-index" class="repertoire-index">
 
 <?php
+// Sort keywords: matched first (alpha), then unmatched (alpha) — keeps viable
+// tags at the top so users don't have to scroll past faded entries.
+usort($repData['keywords'], fn($a, $b) =>
+    ($b['matched'] <=> $a['matched']) ?: strcasecmp($a['value'], $b['value'])
+);
+
 // Render filter columns in the correct left-to-right order.
 // Students column (non-filter) is inserted between keywords and AP/or/fi/years.
 $renderOrder = ['years', 'ap', 'or', 'fi', 'students', 'kw'];