Ajoute endpoint probe health

README.md

@@ -307,6 +307,22 @@ http://guide.your-domain.com/health.php
 
 If you enable demo mode with a `.demo` file, visitors can open the page without the key.
 
+For monitoring tools such as Uptime Kuma, GridTV also exposes a lightweight probe endpoint:
+
+```text
+http://guide.your-domain.com/health.php?format=probe
+```
+
+- returns HTTP `200` when the instance looks healthy
+- returns HTTP `503` when config, PHP extensions, or the first XMLTV source fail
+- returns compact JSON suitable for external monitoring
+
+If you prefer a plain text response:
+
+```text
+http://guide.your-domain.com/health.php?format=probe&plain=1
+```
+
 ---
 
 </details>