fix(downloads): compute storage usage from live file sizes

The storage bar showed 0.00% because calculateTotalDownloadedSize
summed the stored videoFileSize, which is 0 for items downloaded before
the size was recorded (or when fileInfo.size was undefined). Stat the
file on disk and fall back to the stored value.

components/settings/StorageSettings.tsx

@@ -1,4 +1,4 @@
-import { useQuery } from "@tanstack/react-query";
+import { useQuery, useQueryClient } from "@tanstack/react-query";
 import { useTranslation } from "react-i18next";
 import { Alert, Platform, View } from "react-native";
 import { toast } from "sonner-native";
@@ -12,6 +12,7 @@ import { ListItem } from "../list/ListItem";
 export const StorageSettings = () => {
   const { deleteAllFiles, appSizeUsage } = useDownload();
   const { t } = useTranslation();
+  const queryClient = useQueryClient();
   const successHapticFeedback = useHaptic("success");
   const errorHapticFeedback = useHaptic("error");
 
@@ -27,6 +28,8 @@ export const StorageSettings = () => {
         used: (app.total - app.remaining) / app.total,
       };
     },
+    // Keep the bar moving while a download is writing to disk.
+    refetchInterval: 10 * 1000,
   });
 
   const onDeleteClicked = () => {
@@ -48,6 +51,10 @@ export const StorageSettings = () => {
             } catch (_e) {
               errorHapticFeedback();
               toast.error(t("home.settings.toasts.error_deleting_files"));
+            } finally {
+              // Reflect the freed space immediately instead of waiting for
+              // the next poll.
+              queryClient.invalidateQueries({ queryKey: ["appSize"] });
             }
           },
         },