fix: restart-safe entrypoints, remove obsolete compose version

- Add wg0 interface cleanup before startup (prevents 'already exists' crash)
- Always regenerate wg0.conf to pick up key changes
- Remove obsolete 'version' from docker-compose files
- Fix read-only /proc/sys writes (host-level ip_forward already set)

docker-compose.server.yml

@@ -2,7 +2,6 @@
 # docker-compose.server.yml — VPS (сервер с публичным IP)
 # Запуск: docker compose -f docker-compose.server.yml up -d
 # =============================================================================
-version: "3.8"
 
 services:
   wireguard-server: