feat: enhance background image handling with cache-busting

- Added a cache-busting query parameter to the background image URL to ensure the browser reloads the image when updated.
- Updated the AppState to include an optional imageVersion property for managing image updates.
- Modified the BoardBackgroundModal and BoardView components to utilize the new imageVersion for dynamic image loading.

apps/app/src/components/views/board-view.tsx

@@ -1999,7 +1999,11 @@ export function BoardView() {
                   backgroundSettings.imagePath
                 )}&projectPath=${encodeURIComponent(
                   currentProject?.path || ""
-                )})`,
+                )}${
+                  backgroundSettings.imageVersion
+                    ? `&v=${backgroundSettings.imageVersion}`
+                    : ""
+                })`,
                 backgroundSize: "cover",
                 backgroundPosition: "center",
                 backgroundRepeat: "no-repeat",