Fix settings loading and use 2-column card layout.

Merge Flask GET/POST routes, refresh prefs on tab revisit after preload, and reorganize system settings into separate cards.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/common/static/instance_theme.css

@@ -2333,6 +2333,43 @@ html[data-theme="light"] .journal-detail-img-thumb {
   margin-top: 12px;
 }
 
+.settings-page--grid {
+  margin-top: 12px;
+}
+
+.settings-grid-2col {
+  display: grid;
+  grid-template-columns: repeat(2, minmax(0, 1fr));
+  gap: 12px;
+  align-items: start;
+}
+
+.settings-grid-cell {
+  min-width: 0;
+}
+
+.settings-grid-cell--full {
+  grid-column: 1 / -1;
+}
+
+.settings-card--standalone {
+  padding: 12px 14px;
+  height: 100%;
+}
+
+.settings-card--standalone h2 {
+  margin: 0 0 8px;
+  font-size: 1.05rem;
+}
+
+.settings-card--export .settings-export-links-block {
+  display: flex;
+  flex-direction: column;
+  align-items: flex-start;
+  gap: 8px;
+  margin-top: 8px;
+}
+
 .settings-page--ops {
   max-width: 720px;
 }
@@ -2501,6 +2538,9 @@ html[data-theme="light"] .journal-detail-img-thumb {
 }
 
 @media (max-width: 900px) {
+  .settings-grid-2col {
+    grid-template-columns: minmax(0, 1fr);
+  }
   .settings-cards-grid {
     grid-template-columns: minmax(0, 1fr);
   }