diff --git a/apps/mana/apps/web/src/lib/stores/bottom-bar.svelte.ts b/apps/mana/apps/web/src/lib/stores/bottom-bar.svelte.ts
index b4433ecc8..1bb276220 100644
--- a/apps/mana/apps/web/src/lib/stores/bottom-bar.svelte.ts
+++ b/apps/mana/apps/web/src/lib/stores/bottom-bar.svelte.ts
@@ -26,6 +26,17 @@ export const bottomBarStore = {
 		barComponent = component;
 		barProps = props;
 	},
+	/**
+	 * Update only the props of the currently-registered bar component.
+	 * Use this from reactive blocks that frequently produce fresh prop
+	 * objects (e.g. derived arrays) — calling `set(...)` in those
+	 * places needlessly re-writes barComponent every tick, which
+	 * notifies subscribers even when the component identity hasn't
+	 * changed.
+	 */
+	setProps(props: Record<string, unknown>) {
+		barProps = props;
+	},
 	clear() {
 		barComponent = null;
 		barProps = {};
diff --git a/apps/mana/apps/web/src/routes/(app)/+page.svelte b/apps/mana/apps/web/src/routes/(app)/+page.svelte
index 29960b8fa..3279481ee 100644
--- a/apps/mana/apps/web/src/routes/(app)/+page.svelte
+++ b/apps/mana/apps/web/src/routes/(app)/+page.svelte
@@ -121,21 +121,35 @@
 	}
 
 	// ── Register SceneAppBar in the layout's bottom-stack ───
+	// Split into two effects so prop churn (carouselPages re-deriving on
+	// every openApps change) doesn't re-write barComponent. The first
+	// effect handles registration/teardown when scenes appear/disappear;
+	// the second pushes fresh props on every reactive tick.
+	let barRegistered = $state(false);
 	$effect(() => {
-		if (scenes.length > 0) {
-			bottomBarStore.set(SceneAppBar, {
-				scenes,
-				activeSceneId,
-				pages: carouselPages,
-				onSceneSelect: (id: string) => workbenchScenesStore.setActiveScene(id),
-				onSceneCreate: (name: string) => workbenchScenesStore.createScene({ name }),
-				onSceneContextMenu: handleSceneContextMenu,
-				onAppClick: scrollToPage,
-				onAppContextMenu: (e: MouseEvent, id: string) => handleTabContextMenu(e, id),
-				onAddApp: () => (showPicker = !showPicker),
-			});
+		const hasScenes = scenes.length > 0;
+		if (hasScenes && !barRegistered) {
+			bottomBarStore.set(SceneAppBar, {});
+			barRegistered = true;
+		} else if (!hasScenes && barRegistered) {
+			bottomBarStore.clear();
+			barRegistered = false;
 		}
 	});
+	$effect(() => {
+		if (!barRegistered) return;
+		bottomBarStore.setProps({
+			scenes,
+			activeSceneId,
+			pages: carouselPages,
+			onSceneSelect: (id: string) => workbenchScenesStore.setActiveScene(id),
+			onSceneCreate: (name: string) => workbenchScenesStore.createScene({ name }),
+			onSceneContextMenu: handleSceneContextMenu,
+			onAppClick: scrollToPage,
+			onAppContextMenu: (e: MouseEvent, id: string) => handleTabContextMenu(e, id),
+			onAddApp: () => (showPicker = !showPicker),
+		});
+	});
 
 	// ── App CRUD (delegated to active scene) ────────────────
 	function handleAddApp(appId: string) {