chore: update n8n to v1.102.4 and update badges

- Updated n8n from 1.101.1 to 1.102.4
- Updated n8n-core from 1.100.0 to 1.101.2
- Updated n8n-workflow from 1.98.0 to 1.99.1
- Updated @n8n/n8n-nodes-langchain from 1.100.1 to 1.101.2
- Rebuilt node database with 531 nodes
- All validation tests passing
- Updated README.md badges to reflect new versions
- Added reminder to update badges in MEMORY_N8N_UPDATE.md

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

Co-Authored-By: Claude <noreply@anthropic.com>

MEMORY_N8N_UPDATE.md

@@ -79,4 +79,6 @@ To see what would be updated without making changes:
 npm run update:n8n:check
 ```
 
+At the end, update version badges in README.md
+
 This shows you the available updates without modifying anything.