chore: update n8n to 1.123.4 and bump version to 2.28.9 (#478)

- Updated n8n from 1.122.4 to 1.123.4
- Updated n8n-core from 1.121.1 to 1.122.1
- Updated n8n-workflow from 1.119.1 to 1.120.0
- Updated @n8n/n8n-nodes-langchain from 1.121.1 to 1.122.1
- Rebuilt node database with 545 nodes (439 from n8n-nodes-base, 106 from @n8n/n8n-nodes-langchain)
- Updated README badge with new n8n version
- Updated CHANGELOG with dependency changes

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

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Romuald Członkowski <romualdczlonkowski@MacBook-Pro-Romuald.local>
Co-authored-by: Claude <noreply@anthropic.com>

dist/http-server-single-session.js

@@ -106,8 +106,13 @@ class SingleSessionHTTPServer {
             delete this.servers[sessionId];
             delete this.sessionMetadata[sessionId];
             delete this.sessionContexts[sessionId];
-            if (server) {
-                await server.close();
+            if (server && typeof server.close === 'function') {
+                try {
+                    await server.close();
+                }
+                catch (serverError) {
+                    logger_1.logger.warn('Error closing server', { sessionId, error: serverError });
+                }
             }
             if (transport) {
                 await transport.close();