Fix extraction speed: I/O priority only in hybrid mode, more threads

- setWindowsBackgroundIO (Very Low I/O) now only applied in hybrid mode,
  not for all extractions (was causing massive slowdown)
- Hybrid threads changed from -mt1 to half CPU count (e.g. -mt4 on 8-core)
- Move retry count (R9, R22 etc.) from status text to tooltip only

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/renderer/App.tsx

@@ -2890,9 +2890,8 @@ const PackageCard = memo(function PackageCard({ pkg, items, packageSpeed, isFirs
             ) : "-";
           })()}</span>
           <span className="pkg-col pkg-col-hoster" title={formatHoster(item)}>{formatHoster(item)}</span>
-          <span className="pkg-col pkg-col-status" title={item.fullStatus}>
+          <span className="pkg-col pkg-col-status" title={item.retries > 0 ? `${item.fullStatus} · R${item.retries}` : item.fullStatus}>
             {item.fullStatus}
-            {item.retries > 0 && ` · R${item.retries}`}
           </span>
           <span className="pkg-col pkg-col-speed">{item.speedBps > 0 ? formatSpeedMbps(item.speedBps) : "-"}</span>
         </div>