fix(notifications): harden final delivery lifecycle

Enforce one shared shutdown deadline while persisting late digests during blocked sends. Start stall cooldowns from serialized delivery acknowledgements, atomically rewrite cleaned legacy outboxes, retain run summaries for 24 hours, and prevent duplicate history or synthetic post-process start times.

src/main/download-manager.ts

@@ -1963,6 +1963,8 @@ export class DownloadManager extends EventEmitter {
   private successDigestTimer: NodeJS.Timeout | null = null;
 
   private notificationEnqueueChain: Promise<void> = Promise.resolve();
+
+  private notificationsShuttingDown = false;
 
   private itemCount = 0;
 
@@ -8807,6 +8809,7 @@ export class DownloadManager extends EventEmitter {
   }
 
   public async flushNotificationsForShutdown(): Promise<void> {
+    this.notificationsShuttingDown = true;
     this.flushPackageSuccessDigest();
     await this.notificationEnqueueChain;
   }
@@ -12151,6 +12154,10 @@ export class DownloadManager extends EventEmitter {
   private queueSuccessfulPackageResult(envelope: PackageResultEnvelope): void {
     const key = this.packageResultKey(envelope.result.packageId, envelope.generation);
     this.successDigestResults.set(key, envelope);
+    if (this.notificationsShuttingDown) {
+      this.flushPackageSuccessDigest();
+      return;
+    }
     if (this.successDigestTimer) {
       return;
     }
@@ -12219,9 +12226,6 @@ export class DownloadManager extends EventEmitter {
     if (!(pkg.downloadEndedAt || 0)) {
       pkg.downloadEndedAt = completedAt;
     }
-    if (!(pkg.postProcessStartedAt || 0) && (pkg.postProcessQueuedAt || 0) > 0) {
-      pkg.postProcessStartedAt = pkg.postProcessQueuedAt;
-    }
     pkg.postProcessCompletedAt = completedAt;
     pkg.terminalAt = completedAt;
     const result = finalizePackageResult({
@@ -12236,6 +12240,7 @@ export class DownloadManager extends EventEmitter {
     pkg.status = result.status === "partial" ? "failed" : result.status;
     pkg.updatedAt = completedAt;
     if (this.onHistoryEntryCallback) {
+      this.historyRecordedPackages.add(packageId);
       this.onHistoryEntryCallback(buildHistoryEntry(result, {
         generation,
         outputDir: pkg.outputDir,