fix(dashboard): prevent stale saving indicator when desc requests overlap

[AhmetArif0]

Problem

handleSaveDesc and handleAutoDescribe on the Profiles page both set descSaving / describing to true at the start of a request, then unconditionally cleared them in finally:

} finally {
  setDescSaving(false);   // always runs
}

All other side-effects in these handlers are already guarded by if (activeDescRequest.current === name) to ignore stale responses — but the loading flag was not.

Reproduction:

1. Open Profile A's description editor and click Save (request in-flight).
2. Quickly open Profile B's description editor and click Save.
3. Profile A's request resolves → finally fires → setDescSaving(false) clears the indicator even though Profile B's request is still in-flight.
4. The "Saving…" button reverts to "Save" while the write hasn't completed.

The same race exists in handleAutoDescribe with setDescribing.

Fix

Add descSavingCount and describingCount refs that count concurrent in-flight requests. The loading flag is cleared only when the counter reaches zero — i.e. all overlapping requests have settled:

const descSavingCount = useRef(0);

const handleSaveDesc = async (name: string) => {
  descSavingCount.current += 1;
  setDescSaving(true);
  ...
  } finally {
    descSavingCount.current -= 1;
    if (descSavingCount.current === 0) setDescSaving(false);
  }
};

This mirrors the existing activeDescRequest guard pattern already used throughout these handlers.

Test plan

• Open Profile A description editor, click Save, then immediately open Profile B description editor and click Save → "Saving…" stays visible until both writes complete
• Single save (normal case) → loading indicator clears after the single request settles
• Auto-generate description while a manual save is in-flight → describing indicator is not cleared early

[teknium1]

Merged via PR #39070. Your commit was cherry-picked onto current main as de370fd with your authorship preserved in git log. Thanks!