docs: real clone URL in README

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: alantgoff

README.md

@@ -153,7 +153,7 @@ Anthropic SDK, etc.).
 
 ### One-time setup
 ```bash
-git clone <this repo>
+git clone https://github.com/alantgoff/sentinel.git
 cd sentinel
 npm install
 cp .env.example .env