fix(canvas): unify title, improve multi-select drag and immediate delete save

app/canvas/[id]/layout.tsx

@@ -2,7 +2,6 @@ import { Metadata } from "next";
 import { Suspense } from "react";
 
 export const metadata: Metadata = {
-  title: "无限画布",
   description: "AI 驱动的无限画布创作工具",
 };
 

app/canvas/[id]/page.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useEffect, useState, useCallback, use } from "react";
+import { useEffect, useState, useCallback, use, useRef } from "react";
 import { useRouter, useParams } from "next/navigation";
 import useSWR from "swr";
 import { 
@@ -133,6 +133,7 @@ export default function CanvasEditorPage({ params }: PageProps) {
   const [negativePrompt, setNegativePrompt] = useState("");
   const [aspectRatio, setAspectRatio] = useState("1:1");
   const [imageCount, setImageCount] = useState(1);
+  const previousNodeCountRef = useRef(0);
 
   // 获取选中的图片节点
   const selectedImageNode = selectedNodeIds.length === 1 
@@ -191,6 +192,31 @@ export default function CanvasEditorPage({ params }: PageProps) {
     return () => clearTimeout(saveTimer);
   }, [nodes, id, isLoading, getCanvasState]);
 
+  // 删除节点时立即保存，避免用户立刻刷新后看到被删除节点又出现
+  useEffect(() => {
+    if (isLoading) {
+      previousNodeCountRef.current = nodes.length;
+      return;
+    }
+
+    const previousCount = previousNodeCountRef.current;
+    const currentCount = nodes.length;
+    previousNodeCountRef.current = currentCount;
+
+    if (previousCount > currentCount) {
+      const persistAfterDelete = async () => {
+        setIsSaving(true);
+        try {
+          await canvasService.saveCanvasState(id, getCanvasState());
+        } catch (error) {
+          console.error("Delete immediate save failed:", error);
+        }
+        setIsSaving(false);
+      };
+      void persistAfterDelete();
+    }
+  }, [nodes.length, id, isLoading, getCanvasState]);
+
   // 智能命名与缩略图逻辑
   useEffect(() => {
     const autoTitleAndThumbnail = async () => {
@@ -558,7 +584,7 @@ export default function CanvasEditorPage({ params }: PageProps) {
 
         {/* 4. Floating Sidebar (Right) */}
         <div className={cn(
-            "absolute top-4 right-4 bottom-4 z-10 w-[400px] transition-all duration-300 ease-in-out",
+            "absolute top-4 right-4 bottom-4 z-10 w-[460px] max-w-[calc(100vw-1rem)] transition-all duration-300 ease-in-out",
             isPanelOpen ? "translate-x-0 opacity-100" : "translate-x-[120%] opacity-0 pointer-events-none"
         )}>
             <div className="h-full w-full rounded-2xl border bg-background/95 backdrop-blur-md shadow-2xl overflow-hidden flex flex-col">

components/canvas/CanvasChatPanel.tsx

@@ -3705,7 +3705,7 @@ export function CanvasChatPanel({ chatId, initialMessages = [], onClose, onOpenF
           
           {/* Bottom Toolbar */}
           <div className="absolute left-2 bottom-2 right-2 flex items-center gap-2">
-            <div className="flex min-w-0 flex-1 items-center gap-2 overflow-x-auto overscroll-x-contain touch-pan-x pr-1 [scrollbar-width:none] [-ms-overflow-style:none] [&::-webkit-scrollbar]:hidden">
+            <div className="flex min-w-0 flex-1 items-center gap-1.5 overflow-x-visible pr-0.5">
               <input
                 ref={fileInputRef}
                 type="file"

components/canvas/CanvasWorkspace.tsx

@@ -47,6 +47,7 @@ export function CanvasWorkspace() {
   const [containerSize, setContainerSize] = useState({ width: 1920, height: 1080 });
   const dragCounterRef = useRef(0);
   const dragPointerRef = useRef<Position>({ x: 0, y: 0 });
+  const suppressCanvasClickRef = useRef(false);
   const groupDragRef = useRef<{
     nodeId: string;
     startX: number;
@@ -179,6 +180,10 @@ export function CanvasWorkspace() {
   // 处理画布点击（取消选择）
   const handleCanvasClick = useCallback((e: React.MouseEvent) => {
     if (!isEventFromCanvasContainer(e.target)) return;
+    if (suppressCanvasClickRef.current) {
+      suppressCanvasClickRef.current = false;
+      return;
+    }
     if (!isPointOnNodeElement(e.target) && !isMarqueeSelecting) {
       clearSelection();
     }
@@ -247,6 +252,7 @@ export function CanvasWorkspace() {
           .map((node) => node.id);
         if (selectedIds.length > 0) {
           selectNodes(selectedIds);
+          suppressCanvasClickRef.current = true;
         } else {
           clearSelection();
         }