add overflow menu support to pane stack

src/lib/components/ui/PaneStack.svelte

@@ -1,6 +1,7 @@
 <svelte:options runes={true} />
 
 <script lang="ts">
+	import { DropdownMenu } from 'bits-ui'
 	import {
 		type PaneConfig,
 		type PaneStackStore,
@@ -105,10 +106,39 @@
 							element={pane.action.element}
 							elementStyle={!!pane.action.element}
 							onclick={pane.action.handler}
+							disabled={pane.action.disabled}
 						>
 							{pane.action.label}
 						</Button>
 					{/if}
+					{#if pane.overflowMenu && pane.overflowMenu.length > 0}
+						<DropdownMenu.Root>
+							<DropdownMenu.Trigger>
+								{#snippet child({ props })}
+									<Button
+										{...props}
+										variant="ghost"
+										size="small"
+										iconOnly
+										icon="ellipsis"
+										aria-label="More options"
+									/>
+								{/snippet}
+							</DropdownMenu.Trigger>
+							<DropdownMenu.Portal>
+								<DropdownMenu.Content class="overflow-menu" side="bottom" align="end" sideOffset={4}>
+									{#each pane.overflowMenu as item}
+										<DropdownMenu.Item
+											class="overflow-menu-item {item.variant === 'danger' ? 'danger' : ''}"
+											onSelect={item.handler}
+										>
+											{item.label}
+										</DropdownMenu.Item>
+									{/each}
+								</DropdownMenu.Content>
+							</DropdownMenu.Portal>
+						</DropdownMenu.Root>
+					{/if}
 				{/snippet}
 			</SidebarHeader>
 
@@ -256,4 +286,38 @@
 			}
 		}
 	}
+
+	// Overflow menu styles
+	:global(.overflow-menu) {
+		background: var(--menu-bg, white);
+		border: 1px solid var(--border-color, #ddd);
+		border-radius: $card-corner;
+		box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
+		padding: $unit-half;
+		min-width: calc($unit * 20);
+		z-index: 200;
+	}
+
+	:global(.overflow-menu-item) {
+		padding: $unit $unit-2x;
+		border-radius: $item-corner-small;
+		cursor: pointer;
+		font-size: 14px;
+		color: var(--text-primary);
+		outline: none;
+
+		&:hover,
+		&:focus {
+			background: var(--button-bg-hover, #f5f5f5);
+		}
+
+		&.danger {
+			color: var(--danger, #dc3545);
+
+			&:hover,
+			&:focus {
+				background: var(--danger-bg, #fff5f5);
+			}
+		}
+	}
 </style>

src/lib/stores/paneStack.svelte.ts

@@ -13,6 +13,19 @@ export type ElementType = 'wind' | 'fire' | 'water' | 'earth' | 'dark' | 'light'
 /** Context key for pane stack */
 const PANE_STACK_CONTEXT_KEY = Symbol('pane-stack')
 
+export interface PaneAction {
+	label: string
+	handler: () => void
+	element?: ElementType
+	disabled?: boolean
+}
+
+export interface OverflowMenuItem {
+	label: string
+	handler: () => void
+	variant?: 'default' | 'danger'
+}
+
 export interface PaneConfig {
 	/** Unique identifier for this pane */
 	id: string
@@ -25,11 +38,9 @@ export interface PaneConfig {
 	/** Optional callback when back is clicked (for root pane) */
 	onback?: () => void
 	/** Optional save/action button configuration */
-	action?: {
-		label: string
-		handler: () => void
-		element?: ElementType
-	}
+	action?: PaneAction
+	/** Optional overflow menu items */
+	overflowMenu?: OverflowMenuItem[]
 	/** Whether this pane's content should scroll */
 	scrollable?: boolean
 }

src/lib/stores/sidebar.svelte.ts

@@ -2,6 +2,7 @@ import type { Snippet, Component } from 'svelte'
 import {
 	PaneStackStore,
 	type PaneConfig,
+	type OverflowMenuItem,
 	type ElementType
 } from '$lib/stores/paneStack.svelte'
 
@@ -128,30 +129,28 @@ class SidebarStore {
 
 	/**
 	 * Update the action button for the current pane
+	 * @param handler - Click handler, or undefined to show disabled button
+	 * @param label - Button label (defaults to 'Done')
+	 * @param element - Element type for styling
+	 * @param show - Whether to show the button at all (defaults to true if label provided)
 	 */
 	setAction(
-		onsave: (() => void) | undefined,
-		saveLabel?: string,
-		element?: ElementType
+		handler: (() => void) | undefined,
+		label?: string,
+		element?: ElementType,
+		show: boolean = true
 	) {
-		const currentPane = this.paneStack.currentPane
-		if (currentPane) {
-			this.paneStack.updateCurrentProps({})
-			// Update action on current pane
-			const panes = this.paneStack.panes
-			const currentIndex = panes.length - 1
-			if (currentIndex >= 0 && panes[currentIndex]) {
-				panes[currentIndex] = {
-					...panes[currentIndex],
-					action:
-						onsave ?
-							{
-								label: saveLabel ?? 'Done',
-								handler: onsave,
-								element
-							}
-						:	undefined
-				}
+		const panes = this.paneStack.panes
+		const currentIndex = panes.length - 1
+		if (currentIndex >= 0 && panes[currentIndex]) {
+			panes[currentIndex] = {
+				...panes[currentIndex],
+				action: show && label ? {
+					label,
+					handler: handler ?? (() => {}),
+					element,
+					disabled: !handler
+				} : undefined
 			}
 		}
 	}
@@ -163,6 +162,27 @@ class SidebarStore {
 		this.setAction(undefined)
 	}
 
+	/**
+	 * Set the overflow menu items for the current pane
+	 */
+	setOverflowMenu(items: OverflowMenuItem[] | undefined) {
+		const panes = this.paneStack.panes
+		const currentIndex = panes.length - 1
+		if (currentIndex >= 0 && panes[currentIndex]) {
+			panes[currentIndex] = {
+				...panes[currentIndex],
+				overflowMenu: items
+			}
+		}
+	}
+
+	/**
+	 * Clear the overflow menu for the current pane
+	 */
+	clearOverflowMenu() {
+		this.setOverflowMenu(undefined)
+	}
+
 	// Getters for reactive access
 	get isOpen() {
 		return this.state.open