feat(files): add file management UI for scenarios and runs

- add scenario upload and download UI with typed file API helpers
- show run artifacts on run detail pages after polling completes
- handle multipart uploads and absolute file paths for downloads

client/src/pages/session/SessionsPage.tsx

@@ -36,7 +36,10 @@ export function SessionsPage() {
     setLoading(true);
     sessions
       .list(p, limit, orderBy, orderDir === 'asc' ? 'ASC' : 'DESC')
-      .then((res) => { setItems(res.data); setTotal(res.total); })
+      .then((res) => {
+        setItems(res.data);
+        setTotal(res.total);
+      })
       .finally(() => setLoading(false));
   }, []);
 
@@ -64,7 +67,12 @@ export function SessionsPage() {
 
   const columns: TableColumn<Session>[] = [
     { key: 'id', header: t('sessions.col_id'), render: (s) => <UuidBadge id={s.id} />, width: 60 },
-    { key: 'sessionName', header: t('sessions.col_name'), sortable: true, render: (s) => s.sessionName },
+    {
+      key: 'sessionName',
+      header: t('sessions.col_name'),
+      sortable: true,
+      render: (s) => s.sessionName,
+    },
     {
       key: 'status',
       header: t('sessions.col_status'),
@@ -117,7 +125,10 @@ export function SessionsPage() {
         total={total}
         page={page}
         onPageChange={setPage}
-        onPageSizeChange={(s) => { setPageSize(s); setPage(1); }}
+        onPageSizeChange={(s) => {
+          setPageSize(s);
+          setPage(1);
+        }}
         pageSizeOptions={[10, 25, 50]}
         onRowClick={(s) => navigate(`/sessions/${s.id}`)}
       />