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

web/src/lib/canvas/node-registry.ts

@@ -0,0 +1,59 @@
+import { create } from "zustand";
+
+import type { CanvasNodeDefinition } from "@/types/canvas-plugin";
+import { CanvasNodeType } from "@/types/canvas";
+
+const definitions = new Map<string, CanvasNodeDefinition>();
+const ownerByType = new Map<string, string>(); // type -> pluginId(内置为 "builtin")
+
+// 注册表版本号,注册/卸载时自增,驱动创建菜单等 UI 重渲染
+export const useNodeRegistryVersion = create<{ version: number }>(() => ({ version: 0 }));
+function bump() {
+    useNodeRegistryVersion.setState((state) => ({ version: state.version + 1 }));
+}
+
+export function registerNodeDefinitions(defs: CanvasNodeDefinition[], pluginId = "builtin") {
+    defs.forEach((def) => {
+        definitions.set(def.type, def);
+        ownerByType.set(def.type, pluginId);
+    });
+    bump();
+}
+
+export function unregisterPluginNodes(pluginId: string) {
+    for (const [type, owner] of ownerByType) {
+        if (owner !== pluginId) continue;
+        definitions.delete(type);
+        ownerByType.delete(type);
+    }
+    bump();
+}
+
+export function getNodeDefinition(type: string) {
+    return definitions.get(type);
+}
+
+export function getNodePluginId(type: string) {
+    return ownerByType.get(type) || "builtin";
+}
+
+export function listNodeDefinitions() {
+    return Array.from(definitions.values());
+}
+
+export function isRegisteredNodeType(type: string) {
+    return definitions.has(type);
+}
+
+const FALLBACK_SPEC = { width: 340, height: 240, title: "节点", metadata: {} as CanvasNodeDefinition["defaultMetadata"] };
+
+// 提供默认尺寸/标题/初始 metadata,createCanvasNode 与 agent-ops 复用
+export function getNodeSpec(type: string) {
+    const def = definitions.get(type);
+    if (!def) return FALLBACK_SPEC;
+    return { width: def.defaultSize.width, height: def.defaultSize.height, title: def.title, metadata: def.defaultMetadata };
+}
+
+export function isBuiltinNodeType(type: string) {
+    return (Object.values(CanvasNodeType) as string[]).includes(type);
+}