feat(admin): add clickOutside action and update dropdowns

Created a reusable clickOutside Svelte action that dispatches a custom
event when users click outside an element. This replaces manual
document.addEventListener patterns.

Features:
- TypeScript support with generic event types
- Configurable enabled/disabled state
- Optional callback parameter
- Proper cleanup on destroy
- setTimeout to avoid immediate triggering

Updated components to use the new action:
- BaseDropdown.svelte: Removed $effect with manual listeners
- PostDropdown.svelte: Replaced manual click handling

Part of Task 5 - Click-Outside Primitives

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/lib/actions/clickOutside.ts

@@ -0,0 +1,94 @@
+/**
+ * Svelte action that dispatches a 'clickoutside' event when the user clicks outside the element.
+ *
+ * @example
+ * ```svelte
+ * <div use:clickOutside on:clickoutside={() => isOpen = false}>
+ *   Dropdown content
+ * </div>
+ * ```
+ *
+ * @example With options
+ * ```svelte
+ * <div use:clickOutside={{ enabled: isOpen }} on:clickoutside={handleClose}>
+ *   Dropdown content
+ * </div>
+ * ```
+ */
+
+export interface ClickOutsideOptions {
+	/** Whether the action is enabled. Defaults to true. */
+	enabled?: boolean
+	/** Optional callback to execute on click outside. */
+	callback?: () => void
+}
+
+export function clickOutside(
+	element: HTMLElement,
+	options: ClickOutsideOptions | (() => void) = {}
+) {
+	let enabled = true
+	let callback: (() => void) | undefined
+
+	// Normalize options
+	if (typeof options === 'function') {
+		callback = options
+	} else {
+		enabled = options.enabled !== false
+		callback = options.callback
+	}
+
+	function handleClick(event: MouseEvent) {
+		if (!enabled) return
+
+		const target = event.target as Node
+
+		// Check if click is outside the element
+		if (element && !element.contains(target)) {
+			// Dispatch custom event
+			element.dispatchEvent(
+				new CustomEvent('clickoutside', {
+					detail: { target }
+				})
+			)
+
+			// Call callback if provided
+			if (callback) {
+				callback()
+			}
+		}
+	}
+
+	// Add listener on next tick to avoid immediate triggering
+	setTimeout(() => {
+		if (enabled) {
+			document.addEventListener('click', handleClick, true)
+		}
+	}, 0)
+
+	return {
+		update(newOptions: ClickOutsideOptions | (() => void)) {
+			// Remove old listener
+			document.removeEventListener('click', handleClick, true)
+
+			// Normalize new options
+			if (typeof newOptions === 'function') {
+				enabled = true
+				callback = newOptions
+			} else {
+				enabled = newOptions.enabled !== false
+				callback = newOptions.callback
+			}
+
+			// Add new listener if enabled
+			if (enabled) {
+				setTimeout(() => {
+					document.addEventListener('click', handleClick, true)
+				}, 0)
+			}
+		},
+		destroy() {
+			document.removeEventListener('click', handleClick, true)
+		}
+	}
+}

src/lib/components/admin/BaseDropdown.svelte

@@ -2,6 +2,7 @@
 	import type { Snippet } from 'svelte'
 	import Button from './Button.svelte'
 	import DropdownMenuContainer from './DropdownMenuContainer.svelte'
+	import { clickOutside } from '$lib/actions/clickOutside'
 
 	interface Props {
 		isOpen?: boolean
@@ -31,26 +32,17 @@
 		onToggle?.(isOpen)
 	}
 
-	function handleClickOutside(event: MouseEvent) {
-		const target = event.target as HTMLElement
-		if (!target.closest(`.${className}`) && !target.closest('.dropdown-container')) {
-			isOpen = false
-			onToggle?.(false)
-		}
+	function handleClickOutside() {
+		isOpen = false
+		onToggle?.(false)
 	}
-
-	$effect(() => {
-		if (isOpen) {
-			// Use setTimeout to avoid immediate closing when clicking the trigger
-			setTimeout(() => {
-				document.addEventListener('click', handleClickOutside)
-			}, 0)
-			return () => document.removeEventListener('click', handleClickOutside)
-		}
-	})
 </script>
 
-<div class="dropdown-container {className}">
+<div
+	class="dropdown-container {className}"
+	use:clickOutside={{ enabled: isOpen }}
+	on:clickoutside={handleClickOutside}
+>
 	<div class="dropdown-trigger">
 		{@render trigger()}
 

src/lib/components/admin/PostDropdown.svelte

@@ -3,6 +3,7 @@
 	import InlineComposerModal from './InlineComposerModal.svelte'
 	import Button from './Button.svelte'
 	import ChevronDownIcon from '$icons/chevron-down.svg?raw'
+	import { clickOutside } from '$lib/actions/clickOutside'
 
 	let isOpen = $state(false)
 	let buttonRef: HTMLElement
@@ -37,21 +38,12 @@
 		window.location.reload()
 	}
 
-	function handleClickOutside(event: MouseEvent) {
-		if (!buttonRef?.contains(event.target as Node)) {
-			isOpen = false
-		}
+	function handleClickOutside() {
+		isOpen = false
 	}
-
-	$effect(() => {
-		if (isOpen) {
-			document.addEventListener('click', handleClickOutside)
-			return () => document.removeEventListener('click', handleClickOutside)
-		}
-	})
 </script>
 
-<div class="dropdown-container">
+<div class="dropdown-container" use:clickOutside={{ enabled: isOpen }} on:clickoutside={handleClickOutside}>
 	<Button
 		bind:this={buttonRef}
 		variant="primary"