feat(plugin): implement canvas node plugin system with dynamic registration and remote installation

web/src/lib/canvas/plugin-node-context.ts

@@ -0,0 +1,26 @@
+import { createPluginStorage, emitCanvasEvent, onCanvasEvent } from "@/lib/canvas/canvas-event-bus";
+import { getNodePluginId } from "@/lib/canvas/node-registry";
+import type { CanvasTheme } from "@/lib/canvas-theme";
+import type { CanvasNodeData } from "@/types/canvas";
+import type { CanvasNodeContext, CanvasPluginHost } from "@/types/canvas-plugin";
+
+// 把宿主能力 + 节点 + 主题/缩放,组装成注入给插件节点的上下文
+export function buildNodeContext(host: CanvasPluginHost, node: CanvasNodeData, theme: CanvasTheme, scale: number): CanvasNodeContext {
+    const storage = createPluginStorage(getNodePluginId(node.type));
+    return {
+        node,
+        theme,
+        scale,
+        updateMetadata: (patch) => host.updateMetadata(node.id, patch),
+        updateNode: (patch) => host.updateNode(node.id, patch),
+        getNode: (id) => host.getNode(id),
+        getNodes: () => host.getNodes(),
+        getConnections: () => host.getConnections(),
+        getUpstream: () => host.getUpstream(node.id),
+        getDownstream: () => host.getDownstream(node.id),
+        applyOps: (ops) => host.applyOps(ops),
+        emit: (event, payload) => emitCanvasEvent(event, payload),
+        on: (event, handler) => onCanvasEvent(event, handler),
+        storage,
+    };
+}