Fix Traefik configuration issues and improve security

- Upgrade to traefik:latest to fix Docker API compatibility with v29
- Fix websecure entrypoint indentation in traefik.yml
- Remove obsolete DOCKER_API_VERSION environment variable
- Remove incompatible network_mode: host setting
- Set network to external for multi-compose compatibility
- Add environment variable support for certificate email
- Add acme.json to .gitignore for security
- Create acme.json with correct 600 permissions

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

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

traefik.yml

@@ -9,19 +9,18 @@ entryPoints:
         entryPoint:
           to: websecure
           scheme: https
-websecure:
-  address: ":443"
+  websecure:
+    address: ":443"
 
 certificatesResolvers:
   letsencrypt:
     acme:
-      email: votre@email.com
+      email: ${CERT_EMAIL}
       storage: acme.json
       httpChallenge:
         entryPoint: web
 
 providers:
   docker:
-    endpoint: "unix:///var/run/docker.sock"
     exposedByDefault: false
     network: traefik-net