Driver: accept rti_license.dat from source tree, export RTI_LICENSE in container

- Host-side check now also accepts the license at the source tree root
  (checked-in location) instead of only MIGRATE_PIPELINE_ROOT, where it
  does not exist in this checkout
- In-container: export RTI_LICENSE pointing at the mounted license file so
  RTI Connext DDS processes (build tools, ctest) can find it at runtime

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

qt6-after/qt6-migrated-legatus/new_docker_build_release2.sh

@@ -286,9 +286,13 @@ if [[ ! -d "${MIGRATE_PIPELINE_ROOT}" ]]; then
   die "MIGRATE_PIPELINE_ROOT directory does not exist: ${MIGRATE_PIPELINE_ROOT}"
 fi
 
-# Validate rti_license.dat exists (required for DDS builds)
-if [[ "${BUILD_GROUP1}" == "ON" ]] && [[ ! -f "${MIGRATE_PIPELINE_ROOT}/rti_license.dat" ]]; then
-  die "rti_license.dat not found in MIGRATE_PIPELINE_ROOT. Required for DDS builds."
+# Validate rti_license.dat exists (required for DDS builds).
+# The license may live in MIGRATE_PIPELINE_ROOT (CI convention) or, as in this
+# checkout, be checked in at the source tree root.
+if [[ "${BUILD_GROUP1}" == "ON" ]]; then
+  if [[ ! -f "${MIGRATE_PIPELINE_ROOT}/rti_license.dat" ]] && [[ ! -f "${SCRIPT_DIR}/rti_license.dat" ]]; then
+    die "rti_license.dat not found in ${MIGRATE_PIPELINE_ROOT} or ${SCRIPT_DIR}. Required for DDS builds."
+  fi
 fi
 
 log_info "=== Release 2 Build Configuration ==="
@@ -487,6 +491,13 @@ die() {
 
 '"${INSTALL_DEPS}"'
 
+# Point RTI Connext DDS at the license file (checked in at the source tree
+# root) so DDS processes started during the build/ctest can find it.
+if [[ -f "${DOCKER_MOUNT_ROOT}/qt-migration-legatus/qt6-after/qt6-migrated-legatus/rti_license.dat" ]]; then
+  export RTI_LICENSE="${DOCKER_MOUNT_ROOT}/qt-migration-legatus/qt6-after/qt6-migrated-legatus/rti_license.dat"
+  log_info "RTI_LICENSE=${RTI_LICENSE}"
+fi
+
 # Configure CMake
 log_info "Configuring CMake..."
 # Use unique build directory to avoid Docker mount caching issues