feat: deliver the redesigned desktop workspace

Rebuild downloads, link collection, settings, history, and statistics around a responsive desktop shell with compact account and queue tables, contextual navigation, persistent update affordances, unified overlays, and accessible keyboard interactions.

Add safe history-folder reveal IPC, responsive 2560/1920/1366/1120 coverage, deterministic visual fixtures, focused component regressions, and release-tree exclusions for internal working files. Bump the public application version to 2.0.13.

src/renderer/ui/ContextInfoButton.tsx

@@ -0,0 +1,70 @@
+import { Children, Fragment, isValidElement, useId, type ReactElement, type ReactNode } from "react";
+import { Icon } from "./Icon";
+
+export interface ContextInfoButtonProps {
+  contextName: string;
+  content: ReactNode;
+  open: boolean;
+  onOpenChange: (open: boolean) => void;
+}
+
+function hasRenderableContent(content: ReactNode): boolean {
+  if (content === null || content === undefined || typeof content === "boolean") {
+    return false;
+  }
+  if (typeof content === "string") {
+    return content.trim().length > 0;
+  }
+  if (typeof content === "number") {
+    return true;
+  }
+  if (Array.isArray(content)) {
+    return content.some(hasRenderableContent);
+  }
+  if (isValidElement<{ children?: ReactNode }>(content) && content.type === Fragment) {
+    return hasRenderableContent(content.props.children);
+  }
+  if (isValidElement(content)) {
+    return true;
+  }
+  return Children.toArray(content).some(hasRenderableContent);
+}
+
+export function ContextInfoButton({
+  contextName,
+  content,
+  open,
+  onOpenChange
+}: ContextInfoButtonProps): ReactElement | null {
+  const regionId = useId();
+
+  if (!hasRenderableContent(content)) {
+    return null;
+  }
+
+  return (
+    <div className="ui-context-info">
+      <button
+        aria-controls={regionId}
+        aria-expanded={open}
+        aria-label="Informationen"
+        className="ui-context-info-trigger"
+        onClick={() => onOpenChange(!open)}
+        title="Informationen"
+        type="button"
+      >
+        <Icon name="info" size={18} />
+      </button>
+      {open ? (
+        <div
+          aria-label={`Informationen zu ${contextName}`}
+          className="ui-context-info-region"
+          id={regionId}
+          role="region"
+        >
+          {content}
+        </div>
+      ) : null}
+    </div>
+  );
+}