diff --git a/frontend/src/lib/components/copilot/chat/ToolDiffCard.svelte b/frontend/src/lib/components/copilot/chat/ToolDiffCard.svelte
index b360dc3ac5..94e33374c3 100644
--- a/frontend/src/lib/components/copilot/chat/ToolDiffCard.svelte
+++ b/frontend/src/lib/components/copilot/chat/ToolDiffCard.svelte
@@ -13,9 +13,10 @@
 
 	interface Props {
 		message: ToolDisplayMessage
+		hidePreviewChip?: boolean
 	}
 
-	let { message }: Props = $props()
+	let { message, hidePreviewChip = false }: Props = $props()
 
 	const diff = $derived(toolCodeDiff(message))
 	const isStreaming = $derived(Boolean(message.isStreamingArguments))
@@ -56,7 +57,7 @@
 
 	const isRunning = $derived(Boolean(message.isLoading && !message.needsConfirmation))
 	const showPreviewChip = $derived(
-		Boolean(message.previewCard && !message.isLoading && !message.error)
+		Boolean(!hidePreviewChip && message.previewCard && !message.isLoading && !message.error)
 	)
 </script>
 
diff --git a/frontend/src/lib/components/copilot/chat/ToolExecutionDisplay.svelte b/frontend/src/lib/components/copilot/chat/ToolExecutionDisplay.svelte
index 15a7e2ea66..7e92c55c89 100644
--- a/frontend/src/lib/components/copilot/chat/ToolExecutionDisplay.svelte
+++ b/frontend/src/lib/components/copilot/chat/ToolExecutionDisplay.svelte
@@ -197,7 +197,7 @@
 {:else if isRunCard}
 	<RunScriptCard {message} />
 {:else if isDiffCard}
-	<ToolDiffCard {message} />
+	<ToolDiffCard {message} {hidePreviewChip} />
 {:else if planState}
 	<!-- Same lean shape as a tool call below: a header row that collapses into the
 	     transcript, with everything else in one box under it. -->
diff --git a/frontend/src/lib/components/copilot/chat/toolGroups.test.ts b/frontend/src/lib/components/copilot/chat/toolGroups.test.ts
index a4fc4ce0a8..4dd3b376fe 100644
--- a/frontend/src/lib/components/copilot/chat/toolGroups.test.ts
+++ b/frontend/src/lib/components/copilot/chat/toolGroups.test.ts
@@ -187,6 +187,19 @@ describe('groupToolRuns', () => {
 		).toEqual([{ edit: [0, 1, 2] }, { edit: [3, 4] }])
 	})
 
+	it('folds app edits that carry a file diff, but not a script edit with one', () => {
+		const app = { path: 'f/a/x' }
+		const diff = { codeDiff: { before: 'a', after: 'b' } }
+		expect(
+			shape([
+				tool('init_app', app),
+				tool('write_app_file', { ...app, file_path: '/App.tsx' }, diff),
+				tool('delete_app_runnable', { ...app, key: 'greet' }, diff),
+				tool('write_script', { path: 'f/a/s' }, diff)
+			])
+		).toEqual([{ edit: [0, 1, 2] }, 3])
+	})
+
 	it('leaves a flow read that prepares an edit to the edit group, not the lookups before it', () => {
 		const flow = { type: 'flow', path: 'f/a/flow' }
 		expect(
diff --git a/frontend/src/lib/components/copilot/chat/toolGroups.ts b/frontend/src/lib/components/copilot/chat/toolGroups.ts
index 94936d4293..f3e3ad0aa9 100644
--- a/frontend/src/lib/components/copilot/chat/toolGroups.ts
+++ b/frontend/src/lib/components/copilot/chat/toolGroups.ts
@@ -116,7 +116,9 @@ function groupableCall(message: DisplayMessage): ToolDisplayMessage | undefined
 	if (message.needsConfirmation || message.blockedByPlanMode) return undefined
 	if (message.heldForFolderInstructions) return undefined
 	if (message.runForm || message.inspectedRun || message.userQuestion) return undefined
-	if (message.codeDiff || message.imageUrl || message.webSearchSources) return undefined
+	// An app edit's diff covers one file of many, so it stays a row inside the app's group.
+	if (message.codeDiff && EDIT_TOOLS[message.toolName] !== 'app') return undefined
+	if (message.imageUrl || message.webSearchSources) return undefined
 	if (!message.error && webSearchResultOf(message.result)) return undefined
 	// The user's own refusal is a decision, not a failure to fold away.
 	if (message.declinedByUser) return undefined