refactor: header user menu with bits-ui dropdown, collapsible sidebar boards

- Replace manual click-outside menu with DropdownMenu from bits-ui
- Add collapsible boards section in sidebar with chevron toggle
- Add max-height scroll for boards list

src/lib/components/layout/Header.svelte

@@ -1,11 +1,13 @@
 <script lang="ts">
 	import { t } from 'svelte-i18n';
+	import { DropdownMenu } from 'bits-ui';
 	import ThemeToggle from './ThemeToggle.svelte';
 	import LanguageSwitcher from './LanguageSwitcher.svelte';
 	import SearchTrigger from '$lib/components/search/SearchTrigger.svelte';
 	import NotificationBell from '$lib/components/notifications/NotificationBell.svelte';
 	import { ui } from '$lib/stores/ui.svelte.js';
 	import { theme, type BackgroundType } from '$lib/stores/theme.svelte.js';
+	import { goto } from '$app/navigation';
 
 	interface Props {
 		user: { displayName: string; email: string; role: string; avatarUrl?: string | null } | null;
@@ -13,8 +15,10 @@
 
 	let { user }: Props = $props();
 
-	let showUserMenu = $state(false);
-	let showBgMenu = $state(false);
+	function submitLogout() {
+		const form = document.getElementById('logout-form');
+		if (form instanceof HTMLFormElement) form.requestSubmit();
+	}
 
 	const bgOptions: { value: BackgroundType; labelKey: string }[] = [
 		{ value: 'mesh', labelKey: 'bg.mesh' },
@@ -22,20 +26,8 @@
 		{ value: 'aurora', labelKey: 'bg.aurora' },
 		{ value: 'none', labelKey: 'bg.none' }
 	];
-
-	function handleClickOutside(e: MouseEvent) {
-		const target = e.target as HTMLElement;
-		if (!target.closest('.user-menu-container')) {
-			showUserMenu = false;
-		}
-		if (!target.closest('.bg-menu-container')) {
-			showBgMenu = false;
-		}
-	}
 </script>
 
-<svelte:window onclick={handleClickOutside} />
-
 <header
 	class="sticky top-0 z-20 flex h-14 items-center gap-3 border-b border-border bg-background/80 px-4 backdrop-blur-sm"
 >
@@ -70,10 +62,8 @@
 	</div>
 
 	<!-- Background selector -->
-	<div class="bg-menu-container relative">
-		<button
-			type="button"
-			onclick={() => (showBgMenu = !showBgMenu)}
+	<DropdownMenu.Root>
+		<DropdownMenu.Trigger
 			class="inline-flex items-center justify-center rounded-md p-2 text-muted-foreground transition-colors hover:bg-accent hover:text-foreground"
 			title={$t('bg.title')}
 			aria-label={$t('bg.aria_label')}
@@ -91,22 +81,19 @@
 				<path d="M2 12s3-7 10-7 10 7 10 7-3 7-10 7-10-7-10-7z" />
 				<circle cx="12" cy="12" r="3" />
 			</svg>
-		</button>
-
-		{#if showBgMenu}
-			<div
-				class="absolute right-0 top-full mt-1 w-44 rounded-md border border-border bg-popover p-1 shadow-lg"
+		</DropdownMenu.Trigger>
+		<DropdownMenu.Portal>
+			<DropdownMenu.Content
+				class="z-50 w-44 rounded-md border border-border bg-popover p-1 shadow-lg"
+				sideOffset={4}
+				align="end"
 			>
 				{#each bgOptions as opt (opt.value)}
-					<button
-						type="button"
-						onclick={() => {
-							theme.setBackground(opt.value);
-							showBgMenu = false;
-						}}
-						class="flex w-full items-center gap-2 rounded-sm px-2 py-1.5 text-sm transition-colors {theme.backgroundType === opt.value
+					<DropdownMenu.Item
+						class="flex w-full cursor-pointer items-center gap-2 rounded-sm px-2 py-1.5 text-sm transition-colors {theme.backgroundType === opt.value
 							? 'bg-accent text-accent-foreground'
 							: 'text-popover-foreground hover:bg-accent/50'}"
+						onSelect={() => theme.setBackground(opt.value)}
 					>
 						{#if theme.backgroundType === opt.value}
 							<svg
@@ -123,11 +110,11 @@
 							<span class="h-3 w-3"></span>
 						{/if}
 						{$t(opt.labelKey)}
-					</button>
+					</DropdownMenu.Item>
 				{/each}
-			</div>
-		{/if}
-	</div>
+			</DropdownMenu.Content>
+		</DropdownMenu.Portal>
+	</DropdownMenu.Root>
 
 	<!-- Notifications bell (authenticated users only) -->
 	{#if user}
@@ -142,10 +129,8 @@
 
 	<!-- User menu -->
 	{#if user}
-		<div class="user-menu-container relative">
-			<button
-				type="button"
-				onclick={() => (showUserMenu = !showUserMenu)}
+		<DropdownMenu.Root>
+			<DropdownMenu.Trigger
 				class="flex items-center gap-2 rounded-md px-2 py-1.5 text-sm text-foreground transition-colors hover:bg-accent"
 			>
 				<span
@@ -156,21 +141,21 @@
 				{#if !ui.isMobile}
 					<span class="max-w-[120px] truncate text-sm">{user.displayName}</span>
 				{/if}
-			</button>
-
-			{#if showUserMenu}
-				<div
-					class="absolute right-0 top-full mt-1 w-48 rounded-md border border-border bg-popover p-1 shadow-lg"
+			</DropdownMenu.Trigger>
+			<DropdownMenu.Portal>
+				<DropdownMenu.Content
+					class="z-50 w-48 rounded-md border border-border bg-popover p-1 shadow-lg"
+					sideOffset={4}
+					align="end"
 				>
 					<div class="border-b border-border px-3 py-2">
 						<p class="text-sm font-medium text-popover-foreground">{user.displayName}</p>
 						<p class="truncate text-xs text-muted-foreground">{user.email}</p>
 					</div>
 
-					<a
-						href="/settings"
-						onclick={() => (showUserMenu = false)}
-						class="flex w-full items-center gap-2 rounded-sm px-3 py-1.5 text-sm text-popover-foreground transition-colors hover:bg-accent"
+					<DropdownMenu.Item
+						class="flex w-full cursor-pointer items-center gap-2 rounded-sm px-3 py-1.5 text-sm text-popover-foreground transition-colors hover:bg-accent"
+						onSelect={() => goto('/settings')}
 					>
 						<svg
 							class="h-4 w-4"
@@ -186,12 +171,11 @@
 							<circle cx="12" cy="12" r="3" />
 						</svg>
 						{$t('settings.title')}
-					</a>
+					</DropdownMenu.Item>
 
-					<a
-						href="/settings/api-tokens"
-						onclick={() => (showUserMenu = false)}
-						class="flex w-full items-center gap-2 rounded-sm px-3 py-1.5 text-sm text-popover-foreground transition-colors hover:bg-accent"
+					<DropdownMenu.Item
+						class="flex w-full cursor-pointer items-center gap-2 rounded-sm px-3 py-1.5 text-sm text-popover-foreground transition-colors hover:bg-accent"
+						onSelect={() => goto('/settings/api-tokens')}
 					>
 						<svg
 							class="h-4 w-4"
@@ -207,12 +191,14 @@
 							<path d="M7 11V7a5 5 0 0 1 10 0v4" />
 						</svg>
 						API Tokens
-					</a>
+					</DropdownMenu.Item>
 
-					<form method="POST" action="/auth/logout">
-						<button
-							type="submit"
-							class="mt-1 flex w-full items-center gap-2 rounded-sm px-3 py-1.5 text-sm text-popover-foreground transition-colors hover:bg-accent"
+					<DropdownMenu.Separator class="my-1 border-t border-border" />
+
+					<form method="POST" action="/auth/logout" id="logout-form" class="contents">
+						<DropdownMenu.Item
+							class="flex w-full cursor-pointer items-center gap-2 rounded-sm px-3 py-1.5 text-sm text-popover-foreground transition-colors hover:bg-accent"
+							onSelect={submitLogout}
 						>
 							<svg
 								class="h-4 w-4"
@@ -229,11 +215,11 @@
 								<line x1="21" y1="12" x2="9" y2="12" />
 							</svg>
 							{$t('auth.logout')}
-						</button>
+						</DropdownMenu.Item>
 					</form>
-				</div>
-			{/if}
-		</div>
+				</DropdownMenu.Content>
+			</DropdownMenu.Portal>
+		</DropdownMenu.Root>
 	{:else}
 		<a
 			href="/login"

src/lib/components/layout/Sidebar.svelte

@@ -19,6 +19,8 @@
 
 	let { boards, isAdmin, collapsed }: Props = $props();
 
+	let boardsExpanded = $state(true);
+
 	function isActive(path: string): boolean {
 		return $page.url.pathname.startsWith(path);
 	}
@@ -158,13 +160,29 @@
 		{#if boards.length > 0}
 			<div class="mb-3">
 				{#if !collapsed}
-					<p
-						class="mb-1 px-2 text-xs font-medium uppercase tracking-wider text-sidebar-foreground/50"
+					<button
+						type="button"
+						onclick={() => (boardsExpanded = !boardsExpanded)}
+						class="mb-1 flex w-full items-center justify-between px-2 text-xs font-medium uppercase tracking-wider text-sidebar-foreground/50 transition-colors hover:text-sidebar-foreground/80"
 					>
-						{$t('nav.boards')}
-					</p>
+						<span>{$t('nav.boards')}</span>
+						<svg
+							class="h-3 w-3 transition-transform duration-200"
+							class:rotate-180={boardsExpanded}
+							viewBox="0 0 24 24"
+							fill="none"
+							stroke="currentColor"
+							stroke-width="2"
+							stroke-linecap="round"
+							stroke-linejoin="round"
+						>
+							<polyline points="6 9 12 15 18 9" />
+						</svg>
+					</button>
 				{/if}
 
+				{#if boardsExpanded || collapsed}
+					<div class="max-h-48 overflow-y-auto">
 						{#each boards as board (board.id)}
 							<a
 								href="/boards/{board.id}"
@@ -190,6 +208,8 @@
 						{/each}
 					</div>
 				{/if}
+			</div>
+		{/if}
 
 		<!-- Admin -->
 		{#if isAdmin}