fix: implement fail-fast fallback and single-commit git diff strategy #3

	name: Maintenance Push – Fast

	on:
	push:
	branches: ['..x']

	jobs:
	fast-impacted:
	if: contains(github.event.head_commit.message, '(cherry picked from commit')
	runs-on: ubuntu-latest
	permissions:
	contents: read
	concurrency:
	group: ${{ github.workflow }}-${{ github.ref }}
	cancel-in-progress: true
	steps:
	- uses: actions/checkout@v4
	with: { fetch-depth: 0 }

	- run: git fetch origin "$GITHUB_REF_NAME" --depth=1

	- uses: actions/setup-java@v4
	with:
	java-version: '17'
	distribution: 'temurin'
	cache: 'maven'

	- name: Set up Python
	uses: actions/setup-python@v5
	with:
	python-version: '3.11'

	- name: Show commit range
	run: \|
	echo "Base ref: origin/$GITHUB_REF_NAME"
	git log --oneline "origin/$GITHUB_REF_NAME...HEAD"

	- name: Compute impacted modules
	id: mods
	run: \|
	MODS=$(python3 .github/scripts/test_discovery.py modules-from-diff --base "origin/$GITHUB_REF_NAME" --verbose)
	echo "modules=$MODS" >> "$GITHUB_OUTPUT"

	- name: Test affected modules with integration tests
	env:
	OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
	SPRING_AI_OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
	run: \|
	MODS="${{ steps.mods.outputs.modules }}"
	if [ -z "$MODS" ]; then
	echo "ERROR: No modules detected - git diff failed to find changes"
	echo "This likely indicates a problem with the git diff strategy"
	echo "Failing fast to avoid wasted resources and investigate the issue"
	echo "Check the 'Compute impacted modules' step output for debugging info"
	exit 1
	fi
	./mvnw -B -T 1C -Pintegration-tests -DfailIfNoTests=false -pl "$MODS" -amd verify

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