fix(frontend): restore outside-click dismiss, collapse story groups by default

frontend/src/lib/components/ui/ContextMenu.svelte

@@ -1,3 +1,9 @@
+<script lang="ts" module>
+  type PointerHandler = (event: PointerEvent) => void;
+
+  const claimed = new WeakSet<Event>();
+</script>
+
 <script lang="ts">
   import { ContextMenu } from "bits-ui";
   import type { Snippet } from "svelte";
@@ -9,8 +15,6 @@
 
   const { children, menu }: Props = $props();
 
-  type PointerHandler = (event: PointerEvent) => void;
-
   let open = $state(false);
   let suppressClick = false;
 
@@ -21,7 +25,10 @@
       ...props,
       onpointerdown(event: PointerEvent) {
         suppressClick = false;
-        event.stopPropagation();
+        if (claimed.has(event)) {
+          return;
+        }
+        claimed.add(event);
         onpointerdown(event);
       },
       onpointerup(event: PointerEvent) {