fix(export): use default wallpaper for native background

src/lib/exporter/modernVideoExporter.nativeStaticLayout.test.ts

@@ -53,6 +53,7 @@ function createExporter(overrides: Record<string, unknown> = {}) {
 			videoInfo: DecodedVideoInfo,
 			effectiveDurationSec: number,
 		) => string | null;
+		resolveNativeStaticLayoutBackground: () => Promise<unknown>;
 	};
 }
 
@@ -190,6 +191,24 @@ describe("ModernVideoExporter native static-layout eligibility", () => {
 		).toBeNull();
 	});
 
+	it("uses the default wallpaper for native static-layout when the project has no wallpaper", async () => {
+		const exporter = createExporter({ wallpaper: "" });
+		const electronAPI = window.electronAPI as typeof window.electronAPI & {
+			getAssetBasePath: () => Promise<string>;
+			listAssetDirectory: () => Promise<{ success: true; files: string[] }>;
+		};
+		electronAPI.getAssetBasePath = vi.fn(async () => "file:///C:/Recordly/resources/");
+		electronAPI.listAssetDirectory = vi.fn(async () => ({
+			success: true,
+			files: ["tahoe-light.jpg"],
+		}));
+
+		await expect(exporter.resolveNativeStaticLayoutBackground()).resolves.toEqual({
+			backgroundColor: "#101010",
+			backgroundImagePath: "C:/Recordly/resources/wallpapers/tahoe-light.jpg",
+		});
+	});
+
 	it("allows non-tail trim timelines with native static-layout", () => {
 		const exporter = createExporter({
 			trimRegions: [{ id: "trim-1", startMs: 10_000, endMs: 12_000 }],

src/lib/exporter/modernVideoExporter.ts

@@ -40,7 +40,11 @@ import {
 } from "@/components/video-editor/webcamOverlay";
 import { extensionHost } from "@/lib/extensions";
 import { getEffectiveVideoStreamDurationSeconds } from "@/lib/mediaTiming";
-import { DEFAULT_WALLPAPER_RELATIVE_PATH, isVideoWallpaperSource } from "@/lib/wallpapers";
+import {
+	DEFAULT_WALLPAPER_PATH,
+	DEFAULT_WALLPAPER_RELATIVE_PATH,
+	isVideoWallpaperSource,
+} from "@/lib/wallpapers";
 import { AudioProcessor, isAacAudioEncodingSupported } from "./audioEncoder";
 import {
 	getDefaultLightningRenderBackend,
@@ -1261,7 +1265,8 @@ export class ModernVideoExporter {
 	}
 
 	private async resolveNativeStaticLayoutBackground(): Promise<NativeStaticLayoutBackground | null> {
-		const wallpaper = this.config.wallpaper?.trim() ?? "";
+		const configuredWallpaper = this.config.wallpaper?.trim() ?? "";
+		const wallpaper = configuredWallpaper || DEFAULT_WALLPAPER_PATH;
 		if (/^#?[0-9a-f]{6}$/i.test(wallpaper)) {
 			return {
 				backgroundColor: wallpaper.startsWith("#") ? wallpaper : `#${wallpaper}`,
@@ -1270,7 +1275,6 @@ export class ModernVideoExporter {
 		}
 
 		if (
-			!wallpaper ||
 			isVideoWallpaperSource(wallpaper) ||
 			wallpaper.startsWith("data:") ||
 			wallpaper.startsWith("blob:") ||