Add Uptime Kuma monitoring integration with dedicated hooks

Implement Uptime Kuma Push Monitor support with separate hook files
following separation of concerns principle.

Changes:
- Add UPTIME_KUMA_PUSH_URL to .env.example
- Create dedicated uptime-kuma-success.sh hook
- Create dedicated uptime-kuma-error.sh hook
- Update config.yaml to call both ntfy and Uptime Kuma hooks
- Each notification service has its own file for modularity

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.env.example

@@ -29,6 +29,14 @@ NTFY_URL=https://ntfy.sh/your-topic-name
 # Laisser vide si pas d'authentification
 NTFY_USER=username:password
 
+# ============================================
+# MONITORING UPTIME KUMA
+# ============================================
+
+# URL du Push Monitor Uptime Kuma
+# Obtenue depuis Uptime Kuma > Add New Monitor > Type: Push
+UPTIME_KUMA_PUSH_URL=http://uptime-kuma:3001/api/push/YOUR_KEY_HERE
+
 # ============================================
 # OPTIONS AVANCÉES
 # ============================================