Add CI badge and CI section to README

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

@@ -1,5 +1,7 @@
 # ProxDoc - The Proxmox System Doctor
 
+[![Lint](https://code.lotusguild.org/LotusGuild/proxDoc/actions/workflows/lint.yml/badge.svg)](https://code.lotusguild.org/LotusGuild/proxDoc/actions?workflow=lint.yml)
+
 ProxDoc is a comprehensive diagnostic tool for Proxmox server health monitoring and system examination.
 
 ## Features
@@ -137,3 +139,10 @@ Current Version: 1.2.0
 
 #### v1.0.0
 - Initial release
+## CI
+
+| Workflow | Purpose | Triggers |
+|---|---|---|
+| `lint.yml` | shellcheck on all `.sh` files | Every push and PR |
+
+Branch protection is enabled on `main` — the lint check must pass before any PR can merge.