Fix ntfy notification hooks to use Borgmatic 2.0 environment variables

Replace deprecated argument-based parameter passing with environment variables
and dynamic data retrieval for archive names and error messages.

Changes:
- Remove "{archive_name}" and "{error}" placeholders from config.yaml
- Update ntfy-success.sh to retrieve archive name via borgmatic list
- Update ntfy-error.sh to extract error messages from systemd logs
- Add repository information to both notification types

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

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

config.yaml

@@ -75,12 +75,12 @@ commands:
       when: [create]
       run:
           - echo "Exécution hook de succès"
-          - /etc/borgmatic/hooks/ntfy-success.sh "{archive_name}" "{stats}"
+          - /etc/borgmatic/hooks/ntfy-success.sh
 
     - after: error
       run:
           - echo "Exécution hook d'erreur"
-          - /etc/borgmatic/hooks/ntfy-error.sh "{error}"
+          - /etc/borgmatic/hooks/ntfy-error.sh
 
 # Commandes PostgreSQL/MySQL si nécessaire
 # postgresql_databases: