feat: add n8n_generate_workflow tool for hosted workflow generation

Add new MCP tool that enables AI-powered workflow generation from natural
language descriptions. Uses handler delegation pattern — hosting environments
inject a GenerateWorkflowHandler via EngineOptions, self-hosted instances
receive a hosted-only informational response.

Handler flows through N8NMCPEngine → SingleSessionHTTPServer →
N8NDocumentationMCPServer with helpers for createWorkflow, validateWorkflow,
autofixWorkflow, and getWorkflow.

Includes full tool documentation, tests, and corrected tools overview count.

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

dist/mcp/stdio-wrapper.js

@@ -29,6 +29,16 @@ console.table = () => { };
 console.clear = () => { };
 console.count = () => { };
 console.countReset = () => { };
+const originalStdoutWrite = process.stdout.write.bind(process.stdout);
+const stderrWrite = process.stderr.write.bind(process.stderr);
+process.stdout.write = function (chunk, encodingOrCallback, callback) {
+    const str = typeof chunk === 'string' ? chunk : chunk.toString();
+    const trimmed = str.trimStart();
+    if (trimmed.startsWith('{') && trimmed.includes('"jsonrpc"')) {
+        return originalStdoutWrite(chunk, encodingOrCallback, callback);
+    }
+    return stderrWrite(chunk, encodingOrCallback, callback);
+};
 const server_1 = require("./server");
 let server = null;
 async function main() {