Add test infrastructure with Docker services, CLI tools, and resolve Phase 0 questions

Stand up local dev infrastructure (OPC UA, LDAP, MS SQL) with Docker Compose,
Python CLI tools for service interaction, and teardown script. Fix GLAuth config
mount, OPC PLC node format, and document actual DN/namespace behavior discovered
during testing. Resolve Q1-Q8,Q10: .NET 10, Akka.NET 1.5.x, monorepo with slnx,
appsettings JWT, Windows Server 2022 site target.

infra/teardown.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+# Tear down ScadaLink test infrastructure.
+#
+# Usage:
+#   ./teardown.sh           Stop containers and delete the SQL data volume
+#   ./teardown.sh --images  Also remove downloaded Docker images
+#   ./teardown.sh --all     Remove volumes, images, and the Python venv
+
+set -euo pipefail
+cd "$(dirname "$0")"
+
+REMOVE_IMAGES=false
+REMOVE_VENV=false
+
+for arg in "$@"; do
+  case "$arg" in
+    --images) REMOVE_IMAGES=true ;;
+    --all)    REMOVE_IMAGES=true; REMOVE_VENV=true ;;
+    -h|--help)
+      echo "Usage: ./teardown.sh [--images] [--all]"
+      echo "  (no flags)  Stop containers, delete SQL data volume"
+      echo "  --images    Also remove downloaded Docker images"
+      echo "  --all       Remove volumes, images, and Python venv"
+      exit 0
+      ;;
+    *)
+      echo "Unknown option: $arg" >&2
+      exit 1
+      ;;
+  esac
+done
+
+echo "Stopping containers and removing SQL data volume..."
+if $REMOVE_IMAGES; then
+  docker compose down -v --rmi all
+else
+  docker compose down -v
+fi
+
+if $REMOVE_VENV && [ -d tools/.venv ]; then
+  echo "Removing Python virtual environment..."
+  rm -rf tools/.venv
+fi
+
+echo ""
+echo "Teardown complete."
+echo "To start fresh: docker compose up -d && python tools/mssql_tool.py setup --script mssql/setup.sql"