Fix extraction speed and UI label updates

- Change OS priority from IDLE/BELOW_NORMAL to NORMAL/BELOW_NORMAL so
  extraction runs at full speed (matching manual 7-Zip/WinRAR performance)
- Use "high" priority in both hybrid and full extraction paths
- Increase hybrid extraction threads from hardcoded 2 to dynamic
  calculation (half CPU count, min 2, max 8)
- Fix emitState forced emit being silently dropped when a non-forced
  timer was already pending — forced emits now always replace pending
  timers to ensure immediate UI feedback during extraction transitions

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

src/main/download-manager.ts

@@ -3570,14 +3570,16 @@ export class DownloadManager extends EventEmitter {
         this.emit("state", this.getSnapshot());
         return;
       }
-      // Too soon — schedule deferred forced emit
+      // Too soon — replace any pending timer with a shorter forced-emit timer
-      if (!this.stateEmitTimer) {
+      if (this.stateEmitTimer) {
+        clearTimeout(this.stateEmitTimer);
+        this.stateEmitTimer = null;
+      }
       this.stateEmitTimer = setTimeout(() => {
         this.stateEmitTimer = null;
         this.lastStateEmitAt = nowMs();
         this.emit("state", this.getSnapshot());
       }, MIN_FORCE_GAP_MS - sinceLastEmit);
-      }
       return;
     }
     if (this.stateEmitTimer) {
@@ -6400,7 +6402,7 @@ export class DownloadManager extends EventEmitter {
         packageId,
         hybridMode: true,
         maxParallel: this.settings.maxParallelExtract || 2,
-        extractCpuPriority: this.settings.extractCpuPriority,
+        extractCpuPriority: "high",
         onProgress: (progress) => {
           if (progress.phase === "preparing") {
             pkg.postProcessLabel = progress.archiveName || "Vorbereiten...";
@@ -6762,8 +6764,8 @@ export class DownloadManager extends EventEmitter {
           packageId,
           skipPostCleanup: true,
           maxParallel: this.settings.maxParallelExtract || 2,
-          // All downloads finished — use highest configured priority so extraction
+          // All downloads finished — use NORMAL OS priority so extraction runs at
-          // isn't starved. "high" maps to BELOW_NORMAL instead of the default IDLE.
+          // full speed (matching manual 7-Zip/WinRAR speed).
           extractCpuPriority: "high",
           onProgress: (progress) => {
             if (progress.phase === "preparing") {

src/main/extractor.ts

@@ -600,8 +600,8 @@ function extractCpuBudgetFromPriority(priority?: string): number {
 
 function extractOsPriority(priority?: string): number {
   switch (priority) {
-    case "high": return os.constants.priority.PRIORITY_BELOW_NORMAL;
+    case "high": return os.constants.priority.PRIORITY_NORMAL;
-    default: return os.constants.priority.PRIORITY_LOW;
+    default: return os.constants.priority.PRIORITY_BELOW_NORMAL;
   }
 }
 
@@ -615,10 +615,15 @@ function extractCpuBudgetPercent(priority?: string): number {
 
 function extractorThreadSwitch(hybridMode = false, priority?: string): string {
   if (hybridMode) {
-    // 2 threads during hybrid extraction (download + extract simultaneously).
+    // Use half the CPU budget during hybrid extraction to leave headroom for
-    // JDownloader 2 uses in-process 7-Zip-JBinding which naturally limits throughput
+    // concurrent downloads. Falls back to at least 2 threads.
-    // to ~16 MB/s write. 2 UnRAR threads produce similar controlled disk load.
+    const envValue = Number(process.env.RD_EXTRACT_THREADS ?? NaN);
-    return "-mt2";
+    if (Number.isFinite(envValue) && envValue >= 1 && envValue <= 32) {
+      return `-mt${Math.floor(envValue)}`;
+    }
+    const cpuCount = Math.max(1, os.cpus().length || 1);
+    const hybridThreads = Math.max(2, Math.min(8, Math.floor(cpuCount / 2)));
+    return `-mt${hybridThreads}`;
   }
   const envValue = Number(process.env.RD_EXTRACT_THREADS ?? NaN);
   if (Number.isFinite(envValue) && envValue >= 1 && envValue <= 32) {
@@ -640,8 +645,8 @@ function lowerExtractProcessPriority(childPid: number | undefined, cpuPriority?:
     return;
   }
   try {
-    // Lowers CPU scheduling priority so extraction doesn't starve other processes.
+    // Sets CPU scheduling priority for the extraction process.
-    // high → BELOW_NORMAL, middle/low → IDLE. I/O priority stays Normal (like JDownloader 2).
+    // high → NORMAL (full speed), default → BELOW_NORMAL. I/O priority stays Normal.
     os.setPriority(pid, extractOsPriority(cpuPriority));
   } catch {
     // ignore: priority lowering is best-effort