Fix BSOD MEMORY_MANAGEMENT on low-RAM servers

- Dynamically compute JVM -Xmx based on system RAM instead of hardcoded 32g
- Reduce peak memory during session loading (inline JSON string, skip redundant clone)

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

src/main/download-manager.ts

@@ -1409,7 +1409,10 @@ export class DownloadManager extends EventEmitter {
     this.appSessionStartedAt = startedAt;
     this.runtimePersistedTotalMs = Math.max(0, Number(settings.totalRuntimeAllTimeMs || 0));
     this.runtimePersistedAt = startedAt;
-    this.session = cloneSession(session);
+    // loadSession already returns a fresh, standalone object graph — no need to
+    // deep-clone again.  This avoids duplicating the entire session in memory at
+    // startup which can spike peak heap on low-RAM servers.
+    this.session = session;
     this.itemCount = Object.keys(this.session.items).length;
     this.storagePaths = storagePaths;
     this.debridService = new DebridService(settings, {

src/main/extractor.ts

@@ -89,6 +89,14 @@ let resolveExtractorCommandInFlight: Promise<string> | null = null;
 
 const EXTRACTOR_RETRY_AFTER_MS = 30_000;
 const DEFAULT_ZIP_ENTRY_MEMORY_LIMIT_MB = 256;
+
+/** Compute a safe JVM -Xmx value based on available physical RAM.
+ *  Reserves 4 GB for Windows + Electron + other processes, caps at 16 GB. */
+function jvmMaxHeapArg(): string {
+  const totalGb = os.totalmem() / (1024 ** 3);
+  const heapGb = Math.max(1, Math.min(Math.floor(totalGb - 4), 16));
+  return `-Xmx${heapGb}g`;
+}
 const EXTRACTOR_PROBE_TIMEOUT_MS = 8_000;
 const DEFAULT_EXTRACT_CPU_BUDGET_PERCENT = 80;
 let currentExtractCpuPriority: string | undefined;
@@ -1392,7 +1400,7 @@ function startDaemon(layout: JvmExtractorLayout): boolean {
     "-Dfile.encoding=UTF-8",
     `-Djava.io.tmpdir=${jvmTmpDir}`,
     "-Xms1g",
-    "-Xmx32g",
+    jvmMaxHeapArg(),
     "-XX:+UseG1GC",
     "-XX:MaxGCPauseMillis=50",
     "-cp",
@@ -1640,7 +1648,7 @@ async function runJvmExtractCommand(
     "-Dfile.encoding=UTF-8",
     `-Djava.io.tmpdir=${jvmTmpDir}`,
     "-Xms1g",
-    "-Xmx32g",
+    jvmMaxHeapArg(),
     "-XX:+UseG1GC",
     "-XX:MaxGCPauseMillis=50",
     "-cp",

src/main/storage.ts

@@ -721,12 +721,14 @@ export function normalizeLoadedSessionTransientFields(session: SessionState): Se
 
 function readSessionFile(filePath: string): SessionState | null {
   try {
-    const raw = fs.readFileSync(filePath, "utf8");
-    const parsed = JSON.parse(raw) as unknown;
+    // Inline readFileSync into JSON.parse so the raw string is not bound to a
+    // variable and can be GC'd immediately — avoids holding the full JSON text
+    // and the parsed object graph in memory simultaneously.
+    const parsed = JSON.parse(fs.readFileSync(filePath, "utf8")) as unknown;
     const session = normalizeLoadedSessionTransientFields(normalizeLoadedSession(parsed));
     const pkgCount = Object.keys(session.packages).length;
     const itemCount = Object.keys(session.items).length;
-    logger.info(`Session geladen: ${filePath} (${pkgCount} Pakete, ${itemCount} Items, ${raw.length} Bytes)`);
+    logger.info(`Session geladen: ${filePath} (${pkgCount} Pakete, ${itemCount} Items)`);
     return session;
   } catch (error) {
     logger.error(`Session-Datei nicht lesbar: ${filePath}: ${String(error)}`);