feat(canvas): 画布媒体工作流 - 支持批量连线、失败重试与模型能力增强

合并 PR #230。保留当前主线样式与组件结构，吸收批量连线、失败批次重试、媒体模型能力和相关后端增强，并修复集成检查发现的分辨率选择器启用条件与测试稳定性问题。

web/src/pages/canvas/use-canvas-selection-controller.ts

@@ -19,6 +19,7 @@ type UseCanvasSelectionControllerOptions = {
     onCanvasSelectionStart: () => void;
     onNodeInteractionStart: (selectionModifier: boolean) => void;
     onNodeClick: (node: CanvasNodeData) => void;
+    onBatchConnectionTarget?: (event: ReactMouseEvent, nodeId: string) => boolean;
     onDeselect: () => void;
     onSelectionBoxEnd?: () => void;
 };
@@ -57,6 +58,7 @@ export function useCanvasSelectionController({
     onCanvasSelectionStart,
     onNodeInteractionStart,
     onNodeClick,
+    onBatchConnectionTarget,
     onDeselect,
     onSelectionBoxEnd,
 }: UseCanvasSelectionControllerOptions) {
@@ -126,6 +128,7 @@ export function useCanvasSelectionController({
     const handleNodeMouseDown = useCallback((event: ReactMouseEvent, nodeId: string) => {
         event.stopPropagation();
         if (event.button !== 0) return;
+        if (onBatchConnectionTarget?.(event, nodeId)) return;
         setSelectedConnectionId(null);
         const currentNodes = nodesRef.current;
         const nextSelected = new Set(selectedNodeIdsRef.current);
@@ -178,7 +181,7 @@ export function useCanvasSelectionController({
         setIsNodeDragging(true);
         setAlignmentGuides({});
         setDragPreview({ x: 0, y: 0, nodeIds: new Set(initialSelectedNodes.map((item) => item.id)) });
-    }, [historyPausedRef, nodesRef, onNodeClick, onNodeInteractionStart, selectedNodeIdsRef, setSelectedConnectionId, setSelectedNodeIds]);
+    }, [historyPausedRef, nodesRef, onBatchConnectionTarget, onNodeClick, onNodeInteractionStart, selectedNodeIdsRef, setSelectedConnectionId, setSelectedNodeIds]);
 
     const finishNodeDrag = useCallback((clientX?: number, clientY?: number) => {
         if (dragFrameRef.current) {