feat(desktop): DeerFlow visual redesign + stream hang fix + intelligence client

DeerFlow frontend visual overhaul:
- Card-style input box (white rounded card, textarea top, actions bottom)
- Dropdown mode selector (闪速/思考/Pro/Ultra with icons+descriptions)
- Colored quick-action chips (小惊喜/写作/研究/收集/学习)
- Minimal top bar (title + token count + export)
- Warm gray color system (#faf9f6 bg, #f5f4f1 sidebar, #e8e6e1 border)
- DeerFlow-style sidebar (新对话/对话/智能体 nav)
- Reasoning block, tool call chain, task progress visualization
- Streaming text, model selector, suggestion chips components
- Resizable artifact panel with drag handle
- Virtualized message list for 100+ messages

Bug fixes:
- Stream hang: GatewayClient onclose code 1000 now calls onComplete
- WebView2 textarea border: CSS !important override for UA styles
- Gateway stream event handling (response/phase/tool_call types)

Intelligence client:
- Unified client with fallback drivers (compactor/heartbeat/identity/memory/reflection)
- Gateway API types and type conversions

desktop/src/components/ai/ResizableChatLayout.tsx

@@ -0,0 +1,136 @@
+import { useCallback, type ReactNode } from 'react';
+import { Group, Panel, Separator } from 'react-resizable-panels';
+import { X, PanelRightOpen, PanelRightClose } from 'lucide-react';
+
+/**
+ * Resizable dual-panel layout for chat + artifact/detail panel.
+ *
+ * Uses react-resizable-panels v4 API:
+ * - Left panel: Chat area (always visible)
+ * - Right panel: Artifact/detail viewer (collapsible)
+ * - Draggable resize handle between panels
+ * - Persisted panel sizes via localStorage
+ */
+
+interface ResizableChatLayoutProps {
+  chatPanel: ReactNode;
+  rightPanel?: ReactNode;
+  rightPanelTitle?: string;
+  rightPanelOpen?: boolean;
+  onRightPanelToggle?: (open: boolean) => void;
+}
+
+const STORAGE_KEY = 'zclaw-layout-panels';
+const LEFT_PANEL_ID = 'chat-panel';
+const RIGHT_PANEL_ID = 'detail-panel';
+
+function loadPanelSizes(): { left: string; right: string } {
+  try {
+    const stored = localStorage.getItem(STORAGE_KEY);
+    if (stored) {
+      const parsed = JSON.parse(stored);
+      if (parsed.left && parsed.right) {
+        return { left: parsed.left, right: parsed.right };
+      }
+    }
+  } catch { /* ignore */ }
+  return { left: '65%', right: '35%' };
+}
+
+function savePanelSizes(layout: Record<string, number>) {
+  try {
+    const left = layout[LEFT_PANEL_ID];
+    const right = layout[RIGHT_PANEL_ID];
+    if (left !== undefined && right !== undefined) {
+      localStorage.setItem(STORAGE_KEY, JSON.stringify({ left, right }));
+    }
+  } catch { /* ignore */ }
+}
+
+export function ResizableChatLayout({
+  chatPanel,
+  rightPanel,
+  rightPanelTitle = '详情',
+  rightPanelOpen = false,
+  onRightPanelToggle,
+}: ResizableChatLayoutProps) {
+  const sizes = loadPanelSizes();
+
+  const handleToggle = useCallback(() => {
+    onRightPanelToggle?.(!rightPanelOpen);
+  }, [rightPanelOpen, onRightPanelToggle]);
+
+  if (!rightPanelOpen || !rightPanel) {
+    return (
+      <div className="flex-1 flex flex-col overflow-hidden relative">
+        {chatPanel}
+        <button
+          onClick={handleToggle}
+          className="absolute top-3 right-3 z-10 p-1.5 rounded-md bg-white/80 dark:bg-gray-800/80 border border-gray-200 dark:border-gray-700 text-gray-500 dark:text-gray-400 hover:text-gray-700 dark:hover:text-gray-200 hover:bg-white dark:hover:bg-gray-800 transition-colors shadow-sm"
+          title="打开侧面板"
+        >
+          <PanelRightOpen className="w-4 h-4" />
+        </button>
+      </div>
+    );
+  }
+
+  return (
+    <div className="flex-1 flex flex-col overflow-hidden">
+      <Group
+        orientation="horizontal"
+        onLayoutChanged={(layout) => savePanelSizes(layout)}
+      >
+        {/* Left panel: Chat */}
+        <Panel
+          id={LEFT_PANEL_ID}
+          defaultSize={sizes.left}
+          minSize="40%"
+        >
+          <div className="h-full flex flex-col relative">
+            {chatPanel}
+            <button
+              onClick={handleToggle}
+              className="absolute top-3 right-3 z-10 p-1.5 rounded-md bg-white/80 dark:bg-gray-800/80 border border-gray-200 dark:border-gray-700 text-gray-500 dark:text-gray-400 hover:text-gray-700 dark:hover:text-gray-200 hover:bg-white dark:hover:bg-gray-800 transition-colors shadow-sm"
+              title="关闭侧面板"
+            >
+              <PanelRightClose className="w-4 h-4" />
+            </button>
+          </div>
+        </Panel>
+
+        {/* Resize handle */}
+        <Separator className="w-1.5 flex items-center justify-center group cursor-col-resize hover:bg-orange-100 dark:hover:bg-orange-900/20 transition-colors">
+          <div className="w-0.5 h-8 rounded-full bg-gray-300 dark:bg-gray-600 group-hover:bg-orange-400 dark:group-hover:bg-orange-500 transition-colors" />
+        </Separator>
+
+        {/* Right panel: Artifact/Detail */}
+        <Panel
+          id={RIGHT_PANEL_ID}
+          defaultSize={sizes.right}
+          minSize="25%"
+        >
+          <div className="h-full flex flex-col bg-gray-50 dark:bg-gray-900 border-l border-gray-200 dark:border-gray-800">
+            {/* Panel header */}
+            <div className="h-12 flex items-center justify-between px-4 border-b border-gray-200 dark:border-gray-800 flex-shrink-0">
+              <span className="text-xs font-medium text-gray-600 dark:text-gray-400 uppercase tracking-wide">
+                {rightPanelTitle}
+              </span>
+              <button
+                onClick={handleToggle}
+                className="p-1 rounded text-gray-400 hover:text-gray-600 dark:hover:text-gray-200 transition-colors"
+                title="关闭面板"
+              >
+                <X className="w-4 h-4" />
+              </button>
+            </div>
+            {/* Panel content */}
+            <div className="flex-1 overflow-y-auto custom-scrollbar">
+              {rightPanel}
+            </div>
+          </div>
+        </Panel>
+      </Group>
+    </div>
+  );
+}