Fix tooltip CSS issues on Config page

- Allow tooltips to overflow container when section is open
- Expand touch target for tooltip triggers on mobile devices

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/app.css

@@ -579,6 +579,10 @@ body {
     overflow: hidden;
 }
 
+.config-card-content.open > div {
+    overflow: visible;
+}
+
 /* Toggle switches */
 .toggle-group {
     display: flex;
@@ -743,6 +747,15 @@ body {
     user-select: none;
 }
 
+/* Expand touch target for mobile devices */
+@media (pointer: coarse) {
+    .tooltip-trigger::before {
+        content: '';
+        position: absolute;
+        inset: -12px;
+    }
+}
+
 .tooltip-content {
     position: absolute;
     bottom: 140%;