Fix circuit breaker triggering from parallel download failures

- Debounce: simultaneous failures within 2s count as 1 failure
  (prevents 8 parallel unrestrict failures from instant-triggering)
- Raise threshold from 8 to 20 consecutive failures before cooldown
- Escalation tiers: 20→30s, 35→60s, 50→120s, 80+→300s

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "real-debrid-downloader",
-  "version": "1.5.22",
+  "version": "1.5.23",
   "description": "Real-Debrid Downloader Desktop (Electron + React + TypeScript)",
   "main": "build/main/main/main.js",
   "author": "Sucukdeluxe",

src/main/download-manager.ts

@@ -3051,11 +3051,18 @@ export class DownloadManager extends EventEmitter {
     if (entry.lastFailAt > 0 && now - entry.lastFailAt > 120000) {
       entry.count = 0;
     }
+    // Debounce: simultaneous failures (within 2s) count as one failure
+    // This prevents 8 parallel downloads failing at once from immediately hitting the threshold
+    if (entry.lastFailAt > 0 && now - entry.lastFailAt < 2000) {
+      entry.lastFailAt = now;
+      this.providerFailures.set(provider, entry);
+      return;
+    }
     entry.count += 1;
     entry.lastFailAt = now;
-    // Escalating cooldown: 8 failures→30s, 15→60s, 25→120s, 40+→300s
+    // Escalating cooldown: 20 failures→30s, 35→60s, 50→120s, 80+→300s
-    if (entry.count >= 8) {
+    if (entry.count >= 20) {
-      const tier = entry.count >= 40 ? 3 : entry.count >= 25 ? 2 : entry.count >= 15 ? 1 : 0;
+      const tier = entry.count >= 80 ? 3 : entry.count >= 50 ? 2 : entry.count >= 35 ? 1 : 0;
       const cooldownMs = [30000, 60000, 120000, 300000][tier];
       entry.cooldownUntil = now + cooldownMs;
       logger.warn(`Provider Circuit-Breaker: ${provider} ${entry.count} konsekutive Fehler, Cooldown ${cooldownMs / 1000}s`);