Improve Set-Struktur editor: show parent set inline, clamp long descriptions

Removes the per-row indentation (span.ind) in favor of a small "belongs to
set" tag shown above each row's title, so membership is visible without
tracing indentation depth even while sets are expanded. Description text
is now clamped to 2 lines with ellipsis by default and expands to a
scrollable ~12-line view on click.

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

Fuchs/wwwroot/web/fis.inv.de.js

@@ -2656,7 +2656,9 @@ $inv.sets = {
         }
         typ.append($$.s($inv.sets.typLbl(co)));
         $$.tdc('qty', tr).text(co.q || '');
-        let ttl = $$.tdc('ttl', tr).append($$.sc('ind').css('width', (lvl * 1.4).toString() + 'rem')).append($$.s($inv.sets.title(co)));
+        let ttl = $$.tdc('ttl', tr);
+        if (parent !== '') { ttl.append($$.sc('seti', $inv.sets.title(byId[parent]))); }
+        ttl.append($$.sc('txt', $inv.sets.title(co)).click(function (ev) { ev.stopPropagation(); $(this).tC('exp'); }));
         if (isSet) {
             let n = itms.filter((x) => $inv.sets.parentOf(x, byId) === id).length;
             ttl.append($$.sc('cnt', ' (' + n + ')'));