Add support for image background in world settings

src/shared-ui/world-background-style.ts

@@ -2,7 +2,7 @@ import type { CSSProperties } from "react";
 
 import type { WorldBackgroundSettings } from "../document/world-settings";
 
-export function createWorldBackgroundStyle(background: WorldBackgroundSettings): CSSProperties {
+export function createWorldBackgroundStyle(background: WorldBackgroundSettings, imageUrl: string | null = null): CSSProperties {
   if (background.mode === "solid") {
     return {
       backgroundColor: background.colorHex,
@@ -10,6 +10,16 @@ export function createWorldBackgroundStyle(background: WorldBackgroundSettings):
     };
   }
 
+  if (background.mode === "image") {
+    return {
+      backgroundColor: "#0d1116",
+      backgroundImage: imageUrl === null ? "none" : `url("${imageUrl}")`,
+      backgroundPosition: "center center",
+      backgroundRepeat: "no-repeat",
+      backgroundSize: "cover"
+    };
+  }
+
   return {
     backgroundColor: background.bottomColorHex,
     backgroundImage: `linear-gradient(180deg, ${background.topColorHex} 0%, ${background.bottomColorHex} 100%)`