fix: restore container logging compatibility and normalize legacy policies

tests/root_logging.Dockerfile

@@ -0,0 +1,28 @@
+FROM ubuntu:24.04
+
+COPY root-logging-tests /usr/local/bin/root-logging-tests
+
+RUN set -eu; \
+    bucket="$(date -u +%Y-%m-%d)"; \
+    for entrypoint in standard reloadable; do \
+        for destination in file both; do \
+            for format in pretty json; do \
+                for owner in 0 1000 65532 new; do \
+                    directory="/logs/${entrypoint}-${destination}-${format}-${owner}"; \
+                    mkdir -p "${directory}"; \
+                    chown 1000:1000 "${directory}"; \
+                    chmod 0750 "${directory}"; \
+                    if [ "${owner}" != new ]; then \
+                        logfile="${directory}/root-logging-test.${bucket}.log"; \
+                        printf 'historical log\n' >"${logfile}"; \
+                        chown "${owner}:${owner}" "${logfile}"; \
+                        chmod 0640 "${logfile}"; \
+                    fi; \
+                done; \
+            done; \
+        done; \
+    done
+
+USER 0:0
+VOLUME ["/logs"]
+ENTRYPOINT ["/usr/local/bin/root-logging-tests", "--ignored", "--exact", "root_appends_to_existing_logs_without_changing_ownership", "--nocapture"]