fix(library): propagate active scanning spinner icon along full folder path hierarchy to root

docker/frontend/src/Library.tsx

@@ -1099,10 +1099,11 @@ function Catalogue() {
   // so it marks the folder it was asked of.
   const askedMarks = scanQueue().map((j) => markOf(j.folder, j.rel, ''));
   const wearsMark = (n: Node, m: Mark): boolean => {
+    const nKey = normPath(n.key);
     // Another roll's rows are neither the reading's nor the request's news.
-    if (n.key !== m.root && !n.key.startsWith(`${m.root}/`)) return false;
-    // The asked row itself, and every row the asked row sits under.
-    return n.key === m.own || m.own.startsWith(`${n.key}/`);
+    if (nKey !== m.root && !nKey.startsWith(`${m.root}/`)) return false;
+    // The active scanning row itself, and every parent/ancestor row up to root.
+    return nKey === m.own || m.own.startsWith(`${nKey}/`);
   };
 
   // A remembered subfolder that no longer holds a frame falls back to the folder

docker/frontend/src/engine/library.ts

@@ -987,8 +987,9 @@ export async function scanFolder(
       // The frame in hand names the folder the reading is standing in, and the
       // queue is filled layer by layer, so this is the column's answer to which
       // folder is being read while it is being read.
-      const at = rel.lastIndexOf('/');
-      progress.at = at < 0 ? '' : rel.slice(0, at);
+      const relNorm = (rel || '').replace(/\\/g, '/');
+      const cut = relNorm.lastIndexOf('/');
+      progress.at = cut < 0 ? '' : normPath(relNorm.slice(0, cut));
       progress.done++;
       const read = readOne(handle, rel);
       const lane = read