refactor: use floating ui for dropdowns

app/components/Sidenav/Header.vue

@@ -9,7 +9,6 @@ const { user, signOut } = useAuth();
 // particular)
 const cachedUser = ref(user.value);
 
-const dropdownRef = ref<HTMLDivElement | null>(null);
 const dropdownOpen = ref(false);
 
 watch(user, () => {
@@ -29,14 +28,10 @@ const handleLogout = async () => {
 
     await navigateTo('/auth/login');
 };
-
-useClickOutside(dropdownRef, () => {
-    dropdownOpen.value = false;
-});
 </script>
 
 <template>
-    <header ref="dropdownRef" class="flex items-center justify-between overflow-hidden">
+    <header class="flex items-center justify-between overflow-hidden">
         <button @click="dropdownOpen = !dropdownOpen"
             class="flex gap-1 pr-1 items-center hover:bg-[var(--color-hover)] focus-visible:bg-[var(--color-hover)] rounded-lg transition-colors duration-200 ease-[cubic-bezier(0.5,_1,_0.89,_1)]">
             <div
@@ -60,8 +55,8 @@ useClickOutside(dropdownRef, () => {
             enter-from-class="opacity-0 scale-95" enter-to-class="opacity-100 scale-100"
             leave-active-class="transition-all duration-100 ease-[cubic-bezier(0.5,_1,_0.89,_1)]"
             leave-from-class="opacity-100 scale-100" leave-to-class="opacity-0 scale-95">
-            <div v-if="dropdownOpen"
-                class="w-full top-full text-sm mt-1 absolute z-50 bg-[var(--bg-surface)] border border-[var(--color-border)] rounded-xl p-1.5 flex flex-col gap-2">
+            <div v-if="dropdownOpen" v-click-outside="() => dropdownOpen = false"
+                class="w-full top-full text-sm mt-1 absolute z-30 bg-[var(--bg-surface)] border border-[var(--color-border)] rounded-xl p-1.5 flex flex-col gap-2">
                 <button @click="dropdownOpen = false; openDialog(DialogType.Settings)"
                     class="text-left px-3 py-1.5 items-center gap-1 hover:bg-[var(--color-hover)] rounded-lg transition-colors duration-200 ease-[cubic-bezier(0.5,_1,_0.89,_1)]">
                     <span class="i-mynaui-cog-four text-4.5"></span>