Harden against bot floods and add post-provisioning service check

- Traefik rate-limits all routes (60 req/min standard, 300 for Nextcloud)
  and writes access logs to /var/log/traefik/access.log
- Fail2ban watches Traefik access logs and bans IPs after 10 x 403/404
  within 60 s for 24 h
- Nextcloud html directory created as www-data (UID 33) so Apache can
  process .htaccess and serve requests correctly
- scripts/check-services.sh verifies all seven endpoints return the
  expected HTTP status after provisioning

scripts/check-services.sh

@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+# Checks that all service endpoints are reachable and return the expected HTTP
+# status code. Run this after provisioning, before configuring individual services.
+# Usage: bash scripts/check-services.sh
+
+set -uo pipefail
+
+# "url expected_status timeout_seconds" tuples
+# Nextcloud runs its first-time installation on the initial request (1-2 min),
+# so it gets a much longer timeout than the other services.
+CHECKS=(
+  "https://cloud.ladkau.de/dashboard/ 401 10"
+  "https://gitea.ladkau.de 200 10"
+  "https://nextcloud.ladkau.de 200 180"
+  "https://sso.ladkau.de/realms/master 200 10"
+  "https://mail.ladkau.de 200 10"
+  "https://cr.ladkau.de/v2/ 401 10"
+  "https://k8s.ladkau.de 200 10"
+)
+
+if ! command -v curl &>/dev/null; then
+  echo "ERROR: curl not found — install with: apt install curl  or  brew install curl" >&2
+  exit 1
+fi
+
+echo "==> Checking service endpoints"
+
+FAILED=()
+for check in "${CHECKS[@]}"; do
+  read -r url expected timeout <<< "$check"
+
+  if [ "$timeout" -gt 10 ]; then
+    printf "  ...   %s  (first-run setup may take up to %d s)\n" "$url" "$timeout"
+  fi
+
+  actual=$(curl -sL -o /dev/null -w "%{http_code}" --max-time "$timeout" "$url" 2>/dev/null) || actual="000"
+
+  if [ "$actual" = "$expected" ]; then
+    printf "    OK  %s  (%s)\n" "$url" "$actual"
+  else
+    printf "  FAIL  %s  (expected %s, got %s)\n" "$url" "$expected" "$actual"
+    FAILED+=("$url")
+  fi
+done
+
+echo ""
+
+if [ ${#FAILED[@]} -gt 0 ]; then
+  echo "ERROR: ${#FAILED[@]} endpoint(s) did not return the expected status:" >&2
+  for url in "${FAILED[@]}"; do
+    echo "       - ${url}" >&2
+  done
+  echo "" >&2
+  echo "       Check container status on the server: docker ps" >&2
+  echo "       Check container logs: docker logs <container>" >&2
+  echo "       Note: Keycloak and Nextcloud may take longer >90s on first boot — wait and retry." >&2
+  exit 1
+fi
+
+echo "    All services are reachable."