fix(canvas): 活动任务面板 - 恢复顶栏下方偏移并避免遮挡顶部工具 (#162)

* fix(canvas): 活动任务面板 - 恢复顶栏下方偏移并避免遮挡顶部工具

Added topInset prop to CanvasActiveTaskPanel for positioning.

* fix(canvas): 活动任务面板 - 调用侧接入 topInset 让位契约

web/src/pages/canvas/project.tsx

@@ -1538,7 +1538,7 @@ function InfiniteCanvasPage() {
                                 />
                             </InfiniteCanvas>
 
-                            <CanvasActiveTaskPanel tasks={activeTasks} />
+                            <CanvasActiveTaskPanel tasks={activeTasks} topInset={focusMode ? "var(--space-3)" : "var(--canvas-topbar-offset)"} />
 
                             {focusMode ? (
                                 <CanvasFocusModeBar