release: v4.0.0

🎉 Version 4.0.0 - Stable Release

Major Features Now Fully Working:
- Incremental backups (--backup-type incremental --base-backup <path>)
- Notification system (SMTP + webhook via environment variables)
- Full enterprise deployment examples (Ansible, K8s, Terraform)

This release represents feature-complete, production-ready state.

Breaking Changes from v3.x:
- CLI flags synced with documentation
- Notify package now active (reads NOTIFY_* env vars)

Tested:
- All unit tests pass
- go vet clean
- Cross-platform builds successful

README.md

@@ -1,9 +1,19 @@
-# dbbackup
+```
+    ██╗  ██╗    ██████╗ 
+    ██║  ██║   ██╔═████╗
+    ███████║   ██║██╔██║
+    ╚════██║   ████╔╝██║
+         ██║██╗╚██████╔╝
+         ╚═╝╚═╝ ╚═════╝ 
+```
+
+# dbbackup v4.0.0
 
 Database backup and restore utility for PostgreSQL, MySQL, and MariaDB.
 
 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
 [![Go Version](https://img.shields.io/badge/Go-1.21+-00ADD8?logo=go)](https://golang.org/)
+[![Release](https://img.shields.io/badge/Release-v4.0.0-green.svg)](https://github.com/PlusOne/dbbackup/releases/tag/v4.0.0)
 
 **Repository:** https://git.uuxo.net/UUXO/dbbackup  
 **Mirror:** https://github.com/PlusOne/dbbackup