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>

hooks/uptime-kuma-error.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+#
+# Hook Borgmatic - Ping Uptime Kuma en cas d'erreur
+# Borgmatic 2.0 utilise des variables d'environnement
+#
+
+# Charger les variables d'environnement
+if [ -f /etc/borgmatic/.env ]; then
+    source /etc/borgmatic/.env
+fi
+
+# Vérifier que l'URL Uptime Kuma est configurée
+if [ -z "$UPTIME_KUMA_PUSH_URL" ]; then
+    echo "UPTIME_KUMA_PUSH_URL non configuré, ping ignoré"
+    exit 0
+fi
+
+# Ping Uptime Kuma avec status=down
+curl -s "${UPTIME_KUMA_PUSH_URL}?status=down&msg=Backup%20failed&ping=" > /dev/null 2>&1
+
+if [ $? -eq 0 ]; then
+    echo "Ping Uptime Kuma envoyé (error)"
+else
+    echo "Erreur lors du ping Uptime Kuma"
+    exit 1
+fi
+
+exit 0

hooks/uptime-kuma-success.sh

@@ -0,0 +1,28 @@
+#!/bin/bash
+#
+# Hook Borgmatic - Ping Uptime Kuma en cas de succès
+# Borgmatic 2.0 utilise des variables d'environnement
+#
+
+# Charger les variables d'environnement
+if [ -f /etc/borgmatic/.env ]; then
+    source /etc/borgmatic/.env
+fi
+
+# Vérifier que l'URL Uptime Kuma est configurée
+if [ -z "$UPTIME_KUMA_PUSH_URL" ]; then
+    echo "UPTIME_KUMA_PUSH_URL non configuré, ping ignoré"
+    exit 0
+fi
+
+# Ping Uptime Kuma avec status=up
+curl -s "${UPTIME_KUMA_PUSH_URL}?status=up&msg=Backup%20successful&ping=" > /dev/null 2>&1
+
+if [ $? -eq 0 ]; then
+    echo "Ping Uptime Kuma envoyé (success)"
+else
+    echo "Erreur lors du ping Uptime Kuma"
+    exit 1
+fi
+
+exit 0