fix: wire up URL import to home page dropzone and prevent click-through

Pass onUrlImport handler through AppLayout to Dropzone so URL-imported
files are loaded on the home page. Add stopPropagation on the modal
overlay to prevent clicks from reaching elements underneath.

apps/web/src/components/common/url-import-modal.tsx

@@ -88,7 +88,10 @@ export function UrlImportModal({ onClose, onImport }: UrlImportModalProps) {
   }, [handleClose]);
 
   return (
-    <div className="fixed inset-0 z-50 flex items-center justify-center">
+    <div
+      className="fixed inset-0 z-50 flex items-center justify-center"
+      onClick={(e) => e.stopPropagation()}
+    >
       {/* Overlay */}
       <div
         aria-hidden="true"

apps/web/src/components/layout/app-layout.tsx

@@ -18,9 +18,15 @@ interface AppLayoutProps {
   children?: React.ReactNode;
   showToolPanel?: boolean;
   onFiles?: (files: File[]) => void;
+  onUrlImport?: (file: File) => void;
 }
 
-export function AppLayout({ children, showToolPanel = true, onFiles }: AppLayoutProps) {
+export function AppLayout({
+  children,
+  showToolPanel = true,
+  onFiles,
+  onUrlImport,
+}: AppLayoutProps) {
   const [settingsOpen, setSettingsOpen] = useState(false);
   const [helpOpen, setHelpOpen] = useState(false);
   const [mobileSidebarOpen, setMobileSidebarOpen] = useState(false);
@@ -111,7 +117,7 @@ export function AppLayout({ children, showToolPanel = true, onFiles }: AppLayout
 
       <main className={cn("flex-1 flex flex-col overflow-hidden", isMobile && "pt-12 pb-16")}>
         <div className="flex-1 overflow-y-auto p-6 flex items-center justify-center">
-          {children || <Dropzone onFiles={onFiles} accept="image/*" />}
+          {children || <Dropzone onFiles={onFiles} onUrlImport={onUrlImport} accept="image/*" />}
         </div>
         {!isMobile && (
           <div className="text-center text-xs text-muted-foreground py-2 border-t border-border">

apps/web/src/pages/home-page.tsx

@@ -71,11 +71,18 @@ export function HomePage() {
     [setFiles, reset],
   );
 
+  const handleUrlImport = useCallback(
+    (file: File) => {
+      setFiles([file]);
+    },
+    [setFiles],
+  );
+
   const hasFile = files.length > 0;
 
   // If no file uploaded, show default layout (tool panel + dropzone)
   if (!hasFile) {
-    return <AppLayout onFiles={handleFiles} />;
+    return <AppLayout onFiles={handleFiles} onUrlImport={handleUrlImport} />;
   }
 
   // File uploaded — show tool selector on left, image preview on right