Refactor URL normalization to ensure valid wadouri: prefix for DICOM entries

Co-authored-by: Copilot <copilot@github.com>

dicom-viewer/src/main.tsx

@@ -6,9 +6,28 @@ import Nifti from './Nifti.tsx'
 import './index.css'
 import { createImageIds, availableImageIds } from "./lib/createImageIds.ts"
 
-// Helper to convert URLs to wadouri
-const toWadouri = (arr: string[]) =>
-  arr.map(url => url.startsWith("wadouri:") ? url : `wadouri:${url}`);
+// Normalize incoming image ids/URLs and ensure DICOM entries use a valid wadouri: prefix.
+const normalizeImageId = (value: string) => {
+  const trimmed = value.trim();
+  if (!trimmed) return trimmed;
+
+  // Keep non-wadouri schemes untouched.
+  if (trimmed.startsWith("external:") || trimmed.startsWith("wadors:")) {
+    return trimmed;
+  }
+
+  // Fix malformed values like "wadouri::https://..." by removing extra leading colons.
+  if (trimmed.startsWith("wadouri:")) {
+    const rest = trimmed.slice("wadouri:".length).replace(/^:+/, "");
+    return `wadouri:${rest}`;
+  }
+
+  // Also handle malformed absolute URLs such as ":https://...".
+  const sanitized = trimmed.replace(/^:+/, "");
+  return `wadouri:${sanitized}`;
+};
+
+const toWadouri = (arr: string[]) => arr.map(normalizeImageId);
 
 // Normalize a simple array -> descriptor object
 const toDescriptor = (arr: string[] | undefined) => {