refactor: clean repository structure for v0.1.0 open source release

- Remove Go artifacts (cmd/, internal/, pkg/, go.mod)
- Move furt-lua/* content to repository root
- Restructure as clean src/, config/, scripts/, tests/ layout
- Rewrite README.md as practical tool documentation
- Remove timeline references and marketing language
- Clean .gitignore from Go-era artifacts
- Update config/server.lua with example.org defaults
- Add .env.production to .gitignore for security

Repository now ready for open source distribution with minimal,
focused structure and generic configuration templates.
close issue DAW/furt#86

scripts/manual_mail_test.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+# Manual SMTP test with corrected JSON
+
+echo "Testing SMTP with corrected JSON..."
+
+# Simple test without timestamp embedding
+curl -X POST http://127.0.0.1:8080/v1/mail/send \
+     -H "Content-Type: application/json" \
+     -d '{
+       "name": "Furt Test User",
+       "email": "michael@dragons-at-work.de",
+       "subject": "Furt SMTP Test Success!",
+       "message": "This is a test email from Furt Lua HTTP-Server. SMTP Integration working!"
+     }'
+
+echo ""
+echo "Check response above for success:true"
+