fix: stabilize narrow-window telemetry UI

Collect bandwidth history for the full running session, keep responsive service and status labels readable, repair nested menu overflow, and correct semantic state colors.

Update active queue counters immediately for terminal items, add localized integer formatting, eliminate progress label overlap, and cover the regressions with focused tests.

src/renderer/views/downloads/downloads-model.ts

@@ -83,6 +83,14 @@ export function getDownloadQueueTotalBytes(items: Iterable<DownloadItem>): numbe
   return total;
 }
 
+export function getPendingDownloadItemCount(items: Iterable<DownloadItem>): number {
+  let count = 0;
+  for (const item of items) {
+    if (item.status !== "completed" && item.status !== "cancelled" && item.status !== "failed") count += 1;
+  }
+  return count;
+}
+
 export function getDownloadSpeedBps(packageSpeeds: Record<string, number>): number {
   let total = 0;
   for (const speed of Object.values(packageSpeeds)) {