feat: restore GLM 4.7 fixes - auto-scroll and retry logic

Changes from GLM 4.7 Progress Log:

1. Multi-task chat auto-scroll (multi-task-chat.tsx):
   - Added createEffect that monitors message count changes
   - Auto-scrolls using requestAnimationFrame + setTimeout(50ms)
   - Scrolls when new messages arrive or during streaming

2. Electron black screen fix (main.ts):
   - Added exponential backoff retry (1s, 2s, 4s, 8s, 16s max)
   - Added 30-second timeout for load operations
   - Added user-friendly error screen with retry button
   - Handles errno -3 network errors gracefully
   - Max 5 retry attempts before showing error

packages/ui/src/components/chat/multi-task-chat.tsx

@@ -149,6 +149,19 @@ export default function MultiTaskChat(props: MultiTaskChatProps) {
     return () => clearInterval(interval);
   });
 
+  // Auto-scroll when new messages arrive
+  createEffect(() => {
+    const ids = filteredMessageIds();
+    const thinking = isAgentThinking();
+    
+    // Scroll when message count changes or when thinking starts
+    if (ids.length > 0 || thinking) {
+      requestAnimationFrame(() => {
+        setTimeout(scrollToBottom, 50);
+      });
+    }
+  });
+
   const handleSendMessage = async () => {
     const message = chatInput().trim();
     if (!message || isSending()) return;