Adds website theme serialization system

src/app/admin/admin.component.scss

@@ -539,6 +539,60 @@
   font-size: 0.8rem;
 }
 
+// ── Theme export status ──────────────────────────────────
+
+.theme-status-ok,
+.theme-status-missing {
+  padding: $spacing-sm $spacing-md;
+  border-radius: $radius-sm;
+  margin-bottom: $spacing-sm;
+  font-size: 0.88rem;
+  color: $neutral-dark;
+}
+
+.theme-status-ok {
+  background: rgba($success-green, 0.08);
+  border: 1px solid rgba($success-green, 0.25);
+  display: grid;
+  gap: 2px;
+}
+
+.theme-status-missing p {
+  margin: 0 0 $spacing-xs;
+
+  &:last-child {
+    margin-bottom: 0;
+  }
+}
+
+.theme-status-missing {
+  background: rgba($accent-orange, 0.08);
+  border: 1px solid rgba($accent-orange, 0.25);
+}
+
+.btn-outline {
+  background: transparent;
+  border: 2px solid $primary-blue;
+  color: $primary-blue;
+  border-radius: $radius-md;
+  padding: $spacing-xs $spacing-md;
+  font-size: 0.875rem;
+  font-weight: 600;
+  cursor: pointer;
+  transition: background $transition-fast, color $transition-fast;
+  margin-top: $spacing-sm;
+
+  &:hover:not(:disabled) {
+    background: $primary-blue;
+    color: $neutral-white;
+  }
+
+  &:disabled {
+    opacity: 0.6;
+    cursor: not-allowed;
+  }
+}
+
 @include responsive(md) {
   .mobile-build-grid {
     grid-template-columns: 1fr;