feat(jobs): confirm-before-download dialog so users see what's happening

Files were grabbed via a plain anchor with the 'download' attribute, so
clicking the icon just spawned a silent browser download — nothing in
the UI moved, and users (especially labs receiving scans) couldn't tell
whether the click registered.

Wrapped the download button in a confirm dialog that mirrors the existing
delete flow: title 'Dosya indirilsin mi?', filename + size in the body,
Vazgeç / İndir buttons. The 'İndir' button programmatically clicks a
hidden anchor pointing at the /api/.../download proxy and surfaces a
'İndirme başladı.' toast with the filename so there's a clear visual ack
even before the OS download tray pops.

src/app/(dashboard)/jobs/[jobId]/components/job-files-panel.tsx

@@ -242,6 +242,7 @@ function FileRow({ file }: { file: JobFileWithUrl }) {
   );
   const [, startTransition] = useTransition();
   const [open, setOpen] = useState(false);
+  const [downloadOpen, setDownloadOpen] = useState(false);
 
   useEffect(() => {
     if (state.ok) {
@@ -252,6 +253,20 @@ function FileRow({ file }: { file: JobFileWithUrl }) {
     }
   }, [state]);
 
+  function triggerDownload() {
+    // Use a programmatic anchor click — the server route streams the file
+    // with Content-Disposition: attachment, so the browser hands it straight
+    // to the download manager. Toast confirms it left our side.
+    const a = document.createElement("a");
+    a.href = file.url;
+    a.download = file.name;
+    document.body.appendChild(a);
+    a.click();
+    a.remove();
+    setDownloadOpen(false);
+    toast.success("İndirme başladı.", { description: file.name });
+  }
+
   return (
     <li className="flex items-center gap-3 px-3 py-2">
       <span className="text-muted-foreground">{kindIcon(file.kind)}</span>
@@ -264,11 +279,31 @@ function FileRow({ file }: { file: JobFileWithUrl }) {
       <Badge variant="outline" className="hidden sm:inline-flex">
         {JOB_FILE_KIND_LABELS[file.kind] ?? file.kind}
       </Badge>
-      <Button asChild size="sm" variant="outline">
-        <a href={file.url} target="_blank" rel="noopener noreferrer" download={file.name}>
+      <Dialog open={downloadOpen} onOpenChange={setDownloadOpen}>
+        <Button size="sm" variant="outline" onClick={() => setDownloadOpen(true)}>
           <Download className="size-4" />
-        </a>
-      </Button>
+        </Button>
+        <DialogContent>
+          <DialogHeader>
+            <DialogTitle>Dosya indirilsin mi?</DialogTitle>
+            <DialogDescription>
+              <span className="font-medium">{file.name}</span>
+              <span className="text-muted-foreground"> · {formatSize(file.size)}</span>
+            </DialogDescription>
+          </DialogHeader>
+          <DialogFooter>
+            <DialogClose asChild>
+              <Button type="button" variant="outline">
+                Vazgeç
+              </Button>
+            </DialogClose>
+            <Button type="button" onClick={triggerDownload}>
+              <Download className="size-4" />
+              İndir
+            </Button>
+          </DialogFooter>
+        </DialogContent>
+      </Dialog>
       <Dialog open={open} onOpenChange={setOpen}>
         <Button size="sm" variant="outline" onClick={() => setOpen(true)}>
           <Trash2 className="size-4" />