fix(ai-toolbar): align fallback shortcut and identity guards

tests/ai-toolbar.test.ts

@@ -693,6 +693,26 @@ describe("AI toolbar paste capture", () => {
 		expect(onImagesSelect.mock.calls[0]?.[0][0]?.type).toBe("image/png");
 	});
 
+	test("Ctrl+Meta+V does not trigger the async clipboard fallback", async () => {
+		const onImagesSelect = mock();
+		const clipboardRead = mock(async () => []);
+
+		(globalThis as { navigator?: Navigator }).navigator = {
+			clipboard: { read: clipboardRead },
+		} as Navigator;
+
+		await renderToolbar({ onImagesSelect });
+
+		const handleDocumentKeydown = getDocumentListener("keydown");
+
+		await handleDocumentKeydown(
+			createDocumentKeydownEvent({ ctrlKey: true, metaKey: true }),
+		);
+
+		expect(clipboardRead).not.toHaveBeenCalled();
+		expect(onImagesSelect).not.toHaveBeenCalled();
+	});
+
 	test("clipboard fallback creates distinct files for same-sized clipboard images", async () => {
 		const onImagesSelect = mock();
 		const clipboardRead = mock(async () => [
@@ -797,6 +817,51 @@ describe("AI toolbar paste capture", () => {
 		);
 	});
 
+	test("synchronous paste and async fallback normalize identical clipboard payloads to the same file identity", async () => {
+		const syncOnImagesSelect = mock();
+		const asyncOnImagesSelect = mock();
+		const clipboardRead = mock(async () => [
+			{
+				types: ["image/png"],
+				getType: async () => new Blob(["same-image"], { type: "image/png" }),
+			},
+		]);
+
+		(globalThis as { navigator?: Navigator }).navigator = {
+			clipboard: { read: clipboardRead },
+		} as Navigator;
+
+		const { textareaProps } = await renderToolbarBoundary({
+			onImagesSelect: syncOnImagesSelect,
+		});
+		await textareaProps.onPaste?.({
+			clipboardData: createClipboardData([
+				new File(["same-image"], "clipboard.png", { type: "image/png" }),
+			]),
+			preventDefault: mock(),
+		} as unknown as React.ClipboardEvent<HTMLTextAreaElement>);
+		await new Promise((resolve) => setTimeout(resolve, 0));
+
+		registeredDocumentListeners.clear();
+		documentAddEventListener.mockClear();
+		documentRemoveEventListener.mockClear();
+		await renderToolbar({ onImagesSelect: asyncOnImagesSelect });
+		const handleDocumentKeydown = getDocumentListener("keydown");
+
+		await handleDocumentKeydown(
+			createDocumentKeydownEvent({ ctrlKey: true }),
+		);
+
+		expect(syncOnImagesSelect).toHaveBeenCalledTimes(1);
+		expect(asyncOnImagesSelect).toHaveBeenCalledTimes(1);
+		expect(syncOnImagesSelect.mock.calls[0]?.[0][0]?.name).toBe(
+			asyncOnImagesSelect.mock.calls[0]?.[0][0]?.name,
+		);
+		expect(syncOnImagesSelect.mock.calls[0]?.[0][0]?.lastModified).toBe(
+			asyncOnImagesSelect.mock.calls[0]?.[0][0]?.lastModified,
+		);
+	});
+
 	test("async clipboard fallback does not double-handle a paste already handled by the synchronous document paste flow", async () => {
 		const onImagesSelect = mock();
 		const clipboardRead = mock(async () => [