Add migration helpers: migrate_module.sh and MIGRATION_CHECKLIST.md\n\nProvide a repeatable migration script and checklist to standardize adding modules (./Lts, ./...) for Qt6/C++20 migration.\n\nCo-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

migration/migrate_module.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# migration/migrate_module.sh
+# Usage: ./migration/migrate_module.sh <module-path> [--jobs N]
+# Runs a reproducible configure/build/test of the specified module inside the app docker
+
+MODULE_PATH=${1:-}
+if [[ -z "$MODULE_PATH" ]]; then
+  echo "Usage: $0 <module-path> [--jobs N]"
+  exit 1
+fi
+
+JOBS=4
+shift || true
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --jobs) JOBS="$2"; shift 2;;
+    -j*) JOBS="${1#-j}"; shift;;
+    *) echo "Unknown arg: $1"; exit 1;;
+  esac
+done
+
+# Ensure path is relative to repo root
+MODULE_ABS="/repo/$(realpath --relative-to=$(pwd) "$MODULE_PATH")"
+
+# Use app/run_docker.sh to run the migration inside the prepared Qt6 image
+# The container will configure just the requested module in a clean build directory.
+
+./app/run_docker.sh ../sandbox -- bash -lc   "set -euo pipefail && export LD_LIBRARY_PATH=/opt/Qt/6.8.3/gcc_64/lib:\${LD_LIBRARY_PATH:-} && export QT_QPA_PLATFORM=offscreen && rm -rf /repo/build && mkdir -p /repo/build && cd /repo/build && \    cmake -S /repo -B /repo/build -G Ninja -DCMAKE_PREFIX_PATH=/opt/Qt/6.8.3/gcc_64 -DCMAKE_CXX_STANDARD=20 -DMIGRATE_MODULE=${MODULE_PATH} -DBUILD_TESTING=ON && \    cmake --build /repo/build -- -j${JOBS} && ctest --test-dir /repo/build --output-on-failure"
+
+echo "Migration run for module ${MODULE_PATH} finished. Check ./build for logs and artifacts."