fix(release): re-format pom.xml after release:prepare to prevent downstream CI failures

maven-release-plugin rewrites pom.xml files via MavenXpp3Writer which produces
formatting incompatible with xml-format-maven-plugin (e.g. <foo/> becomes <foo />).
The xml-check was already skipped during release:prepare to avoid blocking the release,
but the corrupted formatting was committed to the SNAPSHOT branch, causing CI failures
on any PR opened against the branch after a release.

Fix: run xml-format:xml-format immediately after release:prepare and amend the
SNAPSHOT commit, so the base branch always has correctly formatted pom.xml files.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: 2 people

Makefile

@@ -221,11 +221,15 @@ release-prepare: .require-release-prepare-env
 	@if [[ "${RELEASE_SKIP_TESTS}" == "true" ]] || [[ "${RELEASE_SKIP_TESTS}" == "1" ]]; then
 		export MAVEN_OPTS="${MAVEN_OPTS} -DskipTests=true -DskipITs=true"
 	fi
-	# There is bug in release plugin that leads to pom.xml files being reformatted
-	# Resulted format does not conform to `xml-format-maven-plugin` requirements
-	# As result `release:prepare` stage fails
-	# That is why xml-formatting is disabled here
+	# maven-release-plugin rewrites pom.xml via its own XML serializer (MavenXpp3Writer)
+	# which does not conform to xml-format-maven-plugin rules (e.g. expands <foo/> to <foo />).
+	# The check is skipped during release:prepare to avoid build failure, but we immediately
+	# re-format all pom.xml files and amend the resulting SNAPSHOT commit so that downstream
+	# branches and PRs do not inherit the formatting corruption in their CI merge commits.
 	$(MVNCMD) release:prepare -DpushChanges=false -Dxml-format.skip=true
+	$(MVNCMD) xml-format:xml-format -Dxml-format.skip=false
+	git diff --name-only | grep 'pom\.xml' | xargs --no-run-if-empty git add
+	git diff --cached --quiet || git commit --amend --no-edit
 
 release: .require-release-env
 	@if [[ "${RELEASE_SKIP_TESTS}" == "true" ]] || [[ "${RELEASE_SKIP_TESTS}" == "1" ]]; then