feat(frontend): open sidebar media on click, unbreak long-press menus

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

@@ -8,12 +8,41 @@
   }
 
   const { children, menu }: Props = $props();
+
+  type PointerHandler = (event: PointerEvent) => void;
+
+  let open = $state(false);
+  let suppressClick = false;
+
+  function triggerProps(props: Record<string, unknown>) {
+    const onpointerdown = props.onpointerdown as PointerHandler;
+    const onpointerup = props.onpointerup as PointerHandler;
+    return {
+      ...props,
+      onpointerdown(event: PointerEvent) {
+        suppressClick = false;
+        event.stopPropagation();
+        onpointerdown(event);
+      },
+      onpointerup(event: PointerEvent) {
+        suppressClick = open && event.pointerType !== "mouse";
+        onpointerup(event);
+      },
+      onclickcapture(event: MouseEvent) {
+        if (suppressClick) {
+          suppressClick = false;
+          event.preventDefault();
+          event.stopPropagation();
+        }
+      },
+    };
+  }
 </script>
 
-<ContextMenu.Root>
+<ContextMenu.Root bind:open>
   <ContextMenu.Trigger>
     {#snippet child({ props })}
-      {@render children({ props })}
+      {@render children({ props: triggerProps(props) })}
     {/snippet}
   </ContextMenu.Trigger>
   <ContextMenu.Portal>