Mark the file the folder download is on

During "Download all to a folder" the recipient saw only the file name
under the progress bar. The file's row in the list now shows the loading
indicator while it is on its way, and the list scrolls that row into
view, so a run through hundreds of files can be followed in the list.
The row is scrolled rather than the indicator, which is still hidden
when the run moves on to the file.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

resources/js/share-downloader.js

@@ -68,9 +68,11 @@ document.addEventListener('alpine:init', () => {
             /** How many of the run's files are in the folder. */
             saved: 0,
 
-            /** The file on its way. */
+            /** The file on its way: its path for the status line, its id for its row in the list. */
             current: null,
 
+            currentId: null,
+
             /** The files that failed, kept for the Retry button. */
             failed: [],
 
@@ -140,6 +142,7 @@ document.addEventListener('alpine:init', () => {
                 for (const file of list) {
                     const before = this.received
                     this.current = file.path
+                    this.currentId = file.id
 
                     try {
                         await this.save(file, controller.signal)
@@ -162,6 +165,7 @@ document.addEventListener('alpine:init', () => {
 
                 this.running = false
                 this.current = null
+                this.currentId = null
                 this.finished = ! controller.signal.aborted
             },