feat(agent): implement local Canvas Agent with MCP integration and HTTP server

canvas-agent/src/tools.ts

@@ -0,0 +1,26 @@
+import { toolInputSchemas, toolNames, type ToolName } from "./schemas.js";
+import type { CanvasNode, CanvasSnapshot } from "./types.js";
+
+export function isToolName(name: unknown): name is ToolName {
+    return typeof name === "string" && toolNames.includes(name as ToolName);
+}
+
+export function parseToolInput(name: ToolName, input: unknown) {
+    return toolInputSchemas[name].parse(input ?? {});
+}
+
+export function compactCanvasState(state: CanvasSnapshot | null) {
+    if (!state) throw new Error("当前没有已连接画布");
+    return { ...state, nodes: (state.nodes || []).map(compactNode) };
+}
+
+export function compactNode(node: CanvasNode) {
+    const metadata = { ...(node.metadata || {}) };
+    if (typeof metadata.content === "string" && metadata.content.length > 240) metadata.content = `${metadata.content.slice(0, 120)}...`;
+    return { id: node.id, type: node.type, title: node.title, position: node.position, width: node.width, height: node.height, metadata };
+}
+
+export function nextCanvasX(state: CanvasSnapshot | null) {
+    const nodes = state?.nodes || [];
+    return nodes.length ? Math.max(...nodes.map((node) => node.position.x + node.width)) + 80 : 0;
+}