feat(canvas): add double-click functionality to create nodes from blank canvas area

CHANGELOG.md

@@ -2,15 +2,16 @@
 
 ## Unreleased
 
-+ [优化] 本地 Agent 连接说明明确区分插件 / 手动 MCP 才会增加 Codex token 消耗，直接运行 Agent 不受影响。
++ [新增] 画布空白区域支持双击打开节点选择菜单，并在点击位置创建节点。
++ [优化] 本地 Agent 连接说明明确区分插件 / 手动 MCP 才会增加 Codex token 消耗。
 + [优化] 优化本地 Agent 连接说明，区分 Codex 插件启动和直接运行 Agent 两种方式。
-+ [新增] Agent 对话消息改用 streamdown 流式渲染，提升长回复与 Markdown 内容展示效果。
++ [新增] Agent 对话消息改用 streamdown 流式渲染，提升Markdown 内容展示效果。
-+ [新增] Agent 新增画布、工作台、提示词库和素材等站点级工具，支持读取配置、触发生成与新增素材。
++ [新增] Agent 新增画布、工作台、提示词库和素材等站点级工具。
 + [新增] Agent 面板改为全站常驻右侧栏，开关时同步推动顶栏和页面内容，并保留独立入口按钮。
-+ [新增] Agent 新增 `site_navigate` 工具，支持从对话中直接跳转首页、画布、工作台、素材和配置等页面。
++ [新增] Agent 新增 `site_navigate` 工具，支持页面跳转。
-+ [新增] Agent 对话运行中支持一键停止，发送按钮切换为红色停止按钮并中断当前 Codex turn。
++ [新增] Agent 对话运行中支持一键停止，中断当前 Codex turn。
-+ [调整] Codex 会话改为站点级连续线程，不再按画布 ID 分隔，跨页面和跨画布保持同一上下文。
++ [调整] Codex 会话改为站点级连续线程，跨页面和跨画布保持同一上下文。
-+ [调整] 移除仅前端调用 OpenAI responses 接口的在线画布助手旧逻辑，统一走 MCP + 本地 Codex 链路。
++ [调整] 移除仅前端调用 OpenAI responses 接口，统一走 MCP + 本地 Codex 链路。
 + [新增] 画布节点支持统一维护名称字段，默认显示在节点上方，并可直接双击名称编辑。
 + [新增] 画布新增组节点，支持节点拖入/拆出分组、拖拽高亮吸附和移动组时带动子节点。
 + [调整] 画布节点顶部工具条改为点击选中节点后显示，避免鼠标经过节点时频繁弹出。

docs/content/docs/progress/pending-test.mdx

@@ -5,6 +5,7 @@ description: 当前版本已实现但仍需人工验证的变更项
 
 # 待测试
 
+- 画布节点创建：鼠标左键双击画布空白区域会在点击位置打开节点选择菜单，可创建文本、图片、视频、音频、生成配置和组节点；双击已有节点或连线不应触发菜单。
 - 本地 Agent 连接说明：新增提醒说明只有安装 Codex 插件或手动添加 MCP 后才会增加 Codex token 消耗，直接运行 `npx -y @basketikun/canvas-agent` 不会安装 MCP；需验证文案位置清晰。
 - 本地 Agent 连接说明：画布面板和配置页 Codex Tab 改为区分“Codex 插件启动画布”和“直接运行 Agent 后网页连接”两种方式，需验证文案和布局清晰。
 - 全站 Agent：Agent 面板从画布页抽离为全站常驻面板，挂在全局布局右侧，开/关只挤压左侧内容不遮挡；顶栏和画布工具条各有一个开关按钮，需验证在首页、生图、视频、素材、提示词库、画布等页面都能打开面板并保持 SSE 连接不断开。

web/src/components/canvas/infinite-canvas.tsx

@@ -11,12 +11,13 @@ type InfiniteCanvasProps = {
     onViewportChange: (viewport: ViewportTransform) => void;
     onCanvasMouseDown?: (event: React.PointerEvent<HTMLDivElement>) => void;
     onCanvasDeselect?: () => void;
+    onCanvasDoubleClick?: (event: React.MouseEvent<HTMLDivElement>) => void;
     onContextMenu?: (event: React.MouseEvent) => void;
     onDrop?: (event: React.DragEvent<HTMLDivElement>) => void;
     children: React.ReactNode;
 };
 
-export function InfiniteCanvas({ containerRef, viewport, backgroundMode = "lines", onViewportChange, onCanvasMouseDown, onCanvasDeselect, onContextMenu, onDrop, children }: InfiniteCanvasProps) {
+export function InfiniteCanvas({ containerRef, viewport, backgroundMode = "lines", onViewportChange, onCanvasMouseDown, onCanvasDeselect, onCanvasDoubleClick, onContextMenu, onDrop, children }: InfiniteCanvasProps) {
     const theme = canvasThemes[useThemeStore((state) => state.theme)];
     const panState = useRef({
         isPanning: false,
@@ -116,6 +117,12 @@ export function InfiniteCanvas({ containerRef, viewport, backgroundMode = "lines
         }
     };
 
+    const handleDoubleClick = (event: React.MouseEvent<HTMLDivElement>) => {
+        const target = event.target instanceof Element ? event.target : null;
+        if (target?.closest("[data-canvas-no-zoom],[data-node-id],[data-connection-id]")) return;
+        onCanvasDoubleClick?.(event);
+    };
+
     useEffect(() => {
         const handlePointerMove = (event: PointerEvent) => {
             if (!panState.current.isPanning) return;
@@ -171,6 +178,7 @@ export function InfiniteCanvas({ containerRef, viewport, backgroundMode = "lines
             className="relative h-full w-full cursor-grab select-none overflow-hidden"
             style={{ background: theme.canvas.background }}
             onPointerDown={handlePointerDown}
+            onDoubleClick={handleDoubleClick}
             onWheel={handleWheel}
             onContextMenu={onContextMenu}
             onDragOver={(event) => event.preventDefault()}

web/src/pages/canvas/project.tsx

@@ -1,7 +1,7 @@
 import { useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState } from "react";
 import type { ChangeEvent as ReactChangeEvent, DragEvent as ReactDragEvent, MouseEvent as ReactMouseEvent, PointerEvent as ReactPointerEvent } from "react";
 import { useNavigate, useParams, useSearchParams } from "react-router-dom";
-import { BookOpen, Bot, Home, ImageIcon, Images, List, Menu, Music2, Plus, Redo2, Settings2, Trash2, Undo2, Upload, Video } from "lucide-react";
+import { BookOpen, Bot, Group, Home, ImageIcon, Images, List, Menu, Music2, Plus, Redo2, Settings2, Trash2, Undo2, Upload, Video, X } from "lucide-react";
 import { saveAs } from "file-saver";
 
 import { requestEdit, requestGeneration, requestImageQuestion } from "@/services/api/image";
@@ -212,6 +212,33 @@ function ConnectionCreateOption({ theme, icon, title, description, onClick }: {
     );
 }
 
+function NodeCreateMenu({ position, onCreate, onClose }: { position: Position; onCreate: (type: CanvasNodeType) => void; onClose: () => void }) {
+    const theme = canvasThemes[useThemeStore((state) => state.theme)];
+    return (
+        <div
+            className="absolute z-[120] w-[300px] rounded-[18px] border p-3 shadow-2xl backdrop-blur"
+            data-canvas-no-zoom
+            style={{ left: position.x, top: position.y, background: theme.node.panel, borderColor: theme.node.stroke, color: theme.node.text }}
+            onPointerDown={(event) => event.stopPropagation()}
+        >
+            <div className="mb-2 flex items-center justify-between px-1">
+                <span className="text-sm font-medium" style={{ color: theme.node.muted }}>选择节点</span>
+                <button type="button" className="grid size-7 place-items-center rounded-lg opacity-55 transition hover:opacity-100" onClick={onClose} aria-label="关闭">
+                    <X className="size-4" />
+                </button>
+            </div>
+            <div className="grid gap-1">
+                <ConnectionCreateOption theme={theme} icon={<List className="size-5" />} title="文本" onClick={() => onCreate(CanvasNodeType.Text)} />
+                <ConnectionCreateOption theme={theme} icon={<ImageIcon className="size-5" />} title="图片" onClick={() => onCreate(CanvasNodeType.Image)} />
+                <ConnectionCreateOption theme={theme} icon={<Video className="size-5" />} title="视频" onClick={() => onCreate(CanvasNodeType.Video)} />
+                <ConnectionCreateOption theme={theme} icon={<Music2 className="size-5" />} title="音频" onClick={() => onCreate(CanvasNodeType.Audio)} />
+                <ConnectionCreateOption theme={theme} icon={<Settings2 className="size-5" />} title="生成配置" onClick={() => onCreate(CanvasNodeType.Config)} />
+                <ConnectionCreateOption theme={theme} icon={<Group className="size-5" />} title="组" onClick={() => onCreate(CanvasNodeType.Group)} />
+            </div>
+        </div>
+    );
+}
+
 function InfiniteCanvasPage() {
     const { message, modal } = App.useApp();
     const params = useParams<{ id: string }>();
@@ -281,6 +308,7 @@ function InfiniteCanvasPage() {
     const [mouseWorld, setMouseWorld] = useState<Position>({ x: 0, y: 0 });
     const [selectionBox, setSelectionBox] = useState<SelectionBox | null>(null);
     const [contextMenu, setContextMenu] = useState<ContextMenuState | null>(null);
+    const [nodeCreatePosition, setNodeCreatePosition] = useState<Position | null>(null);
     const [runningNodeId, setRunningNodeId] = useState<string | null>(null);
     const [isMiniMapOpen, setIsMiniMapOpen] = useState(false);
     const [backgroundMode, setBackgroundMode] = useState<CanvasBackgroundMode>("lines");
@@ -1033,6 +1061,7 @@ function InfiniteCanvasPage() {
     const handleCanvasMouseDown = useCallback(
         (event: ReactPointerEvent<HTMLDivElement>) => {
             setContextMenu(null);
+            setNodeCreatePosition(null);
             if (pendingConnectionCreateRef.current) cancelPendingConnectionCreate();
             if (event.button !== 0) return;
 
@@ -1433,6 +1462,7 @@ function InfiniteCanvasPage() {
                 setSelectedNodeIds(new Set());
                 setSelectedConnectionId(null);
                 setContextMenu(null);
+                setNodeCreatePosition(null);
                 setSelectionBox(null);
                 setConnecting(null);
                 setHoveredNodeId(null);
@@ -2505,6 +2535,10 @@ function InfiniteCanvasPage() {
                     }}
                     onCanvasMouseDown={handleCanvasMouseDown}
                     onCanvasDeselect={deselectCanvas}
+                    onCanvasDoubleClick={(event) => {
+                        setContextMenu(null);
+                        setNodeCreatePosition(screenToCanvas(event.clientX, event.clientY));
+                    }}
                     onContextMenu={preventCanvasContextMenu}
                     onDrop={handleDrop}
                 >
@@ -2643,6 +2677,16 @@ function InfiniteCanvasPage() {
                         />
                     ) : null}
                     {pendingConnectionCreate ? <ConnectionCreateMenu pending={pendingConnectionCreate} onCreate={(type) => createConnectedNode(type, pendingConnectionCreate)} onClose={cancelPendingConnectionCreate} /> : null}
+                    {nodeCreatePosition ? (
+                        <NodeCreateMenu
+                            position={nodeCreatePosition}
+                            onCreate={(type) => {
+                                createNode(type, nodeCreatePosition);
+                                setNodeCreatePosition(null);
+                            }}
+                            onClose={() => setNodeCreatePosition(null)}
+                        />
+                    ) : null}
                 </InfiniteCanvas>
 
                 <CanvasNodeHoverToolbar