fix: harden account rotation and active download recovery

Apply account enablement changes optimistically and persist rapid toggles sequentially without losing clicks.

Refresh Mega-Debrid API and Web account pools during active downloads, isolate per-account cancellation budgets, rotate within the same conversion attempt, and keep pause, stop, resume, reset, and no-account gates consistent.

Use the native Electron clipboard under Remote Desktop and make support bundle export bounded, redacted, responsive, guarded, visible, and atomic.

Add end-to-end regressions for live account switching, persisted partial recovery, support export, native copy, availability preservation, and the 500 ms telemetry cadence.

src/renderer/account-toggle-queue.ts

@@ -0,0 +1,72 @@
+import type { DebridProvider, RendererSettingsUpdate } from "../shared/types";
+
+export type AccountToggleTarget =
+  | { kind: "provider"; provider: DebridProvider }
+  | { kind: "debridlink"; accountId: string }
+  | { kind: "mega-api"; accountId: string }
+  | { kind: "mega-web"; accountId: string };
+
+export interface AccountToggleSettings {
+  disabledProviders: DebridProvider[];
+  debridLinkDisabledKeyIds: string[];
+  megaDebridDisabledAccountIds: string[];
+  megaDebridApiDisabledAccountIds: string[];
+  megaDebridWebDisabledAccountIds: string[];
+}
+
+function setListEntry<T extends string>(values: T[], value: T, present: boolean): T[] {
+  return present
+    ? [...new Set([...values, value])]
+    : values.filter((entry) => entry !== value);
+}
+
+export function setAccountTargetEnabled<T extends AccountToggleSettings>(
+  settings: T,
+  target: AccountToggleTarget,
+  enabled: boolean
+): T {
+  if (target.kind === "provider") {
+    return {
+      ...settings,
+      disabledProviders: setListEntry(settings.disabledProviders, target.provider, !enabled)
+    };
+  }
+  if (target.kind === "debridlink") {
+    return {
+      ...settings,
+      debridLinkDisabledKeyIds: setListEntry(settings.debridLinkDisabledKeyIds, target.accountId, !enabled)
+    };
+  }
+  const apiDisabled = target.kind === "mega-api"
+    ? setListEntry(settings.megaDebridApiDisabledAccountIds, target.accountId, !enabled)
+    : settings.megaDebridApiDisabledAccountIds;
+  const webDisabled = target.kind === "mega-web"
+    ? setListEntry(settings.megaDebridWebDisabledAccountIds, target.accountId, !enabled)
+    : settings.megaDebridWebDisabledAccountIds;
+  return {
+    ...settings,
+    megaDebridApiDisabledAccountIds: apiDisabled,
+    megaDebridWebDisabledAccountIds: webDisabled,
+    megaDebridDisabledAccountIds: [...new Set([...apiDisabled, ...webDisabled])]
+  };
+}
+
+export function buildAccountToggleSettingsUpdate(settings: AccountToggleSettings): RendererSettingsUpdate {
+  return {
+    disabledProviders: settings.disabledProviders,
+    debridLinkDisabledKeyIds: settings.debridLinkDisabledKeyIds,
+    megaDebridDisabledAccountIds: settings.megaDebridDisabledAccountIds,
+    megaDebridApiDisabledAccountIds: settings.megaDebridApiDisabledAccountIds,
+    megaDebridWebDisabledAccountIds: settings.megaDebridWebDisabledAccountIds
+  };
+}
+
+export class SerialTaskQueue {
+  private tail: Promise<void> = Promise.resolve();
+
+  public enqueue<T>(task: () => Promise<T>): Promise<T> {
+    const result = this.tail.then(task);
+    this.tail = result.then(() => undefined, () => undefined);
+    return result;
+  }
+}