FINERACT-2436: Add github action to enforce one commit per user in a PR

- added github action to check that one commit per user standard is enforced.
- also checks for whether user has git email properly configured to one registered in github.

Author: edk12564

.github/workflows/pr-one-commit-per-user-check.yml

@@ -0,0 +1,57 @@
+name: Fineract PR One Commit Per User Check
+
+
+on:
+ pull_request:
+   types: [opened, reopened, synchronize]
+
+
+permissions:
+ pull-requests: write
+
+
+jobs:
+ verify-commits:
+   name: Validate One Commit Per User
+   runs-on: ubuntu-latest
+   timeout-minutes: 1
+   steps:
+     - name: Verify Commit Policy
+       id: check
+       env:
+         GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+       run: |
+
+         commits=$(gh api "repos/${{ github.repository }}/pulls/${{ github.event.pull_request.number }}/commits") || { echo "::error::GitHub API request failed"; exit 1; }
+
+         if echo "$commits" | jq -e '.[] | select(.author == null)' > /dev/null; then
+           echo "null_authors=true" >> $GITHUB_OUTPUT
+           echo "::error::Some commits have a git email that is not linked to a GitHub account. Please ensure your git email matches one of your GitHub Account emails."
+           exit 1
+         fi
+
+         user_ids=$(echo "$commits" | jq -r '.[] | select(.author.type != "Bot") | .author.id')
+         if echo "$user_ids" | sort | uniq -d | grep -q .; then
+           echo "multiple_commits=true" >> $GITHUB_OUTPUT
+           echo "::error::Multiple commits from the same author have been detected."
+           exit 1
+         fi
+
+         echo "Success: Each author has exactly one commit."
+
+     - name: Comment on PR
+       if: failure()
+       env:
+         GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+       run: |
+
+         if [ "${{ steps.check.outputs.null_authors }}" == "true" ]; then
+           gh pr comment ${{ github.event.pull_request.number }} --repo ${{ github.repository }} --body \
+         $'**One Commit Per User Check Failed**\n\nSome committers have a git email that does not match their GitHub account. Please ensure your git email matches one of your GitHub Account emails.'
+         fi
+
+
+         if [ "${{ steps.check.outputs.multiple_commits }}" == "true" ]; then
+           gh pr comment ${{ github.event.pull_request.number }} --repo ${{ github.repository }} --body \
+         $'**One Commit Per User Check Failed**\n\nEach user may only have one commit per PR. Please squash your commits.'
+         fi