feat(canvas): 媒体转换节点 - 改进操作选择并支持完成后作为生成参考

Co-authored-by: Cursor <cursoragent@cursor.com>

web/src/lib/canvas/node-registry/definitions/builtin-nodes.tsx

@@ -168,7 +168,7 @@ const BUILTIN_NODE_TRAITS = {
     [CanvasNodeType.MediaConversion]: {
         label: "转换",
         icon: <WandSparkles />,
-        minSize: { width: 320, height: 360 },
+        minSize: { width: 400, height: 360 },
         showInCreateMenu: true,
         resourceKind: (node: CanvasNodeData) => {
             const conversion = node.metadata?.mediaConversion;