fix: detect merge commits, add API connectivity test in CI

.gitea/workflows/codeant.yml

@@ -43,6 +43,16 @@ jobs:
           echo "Base URL: $(codeant get-base-url)"
           echo "CLI version: $(codeant --version)"
 
+          echo "=== API connectivity test ==="
+          HTTP_CODE=$(curl -s -o /tmp/api_response.txt -w "%{http_code}" \
+            -H "Authorization: Bearer ${CODEANT_API_KEY:-}" \
+            -H "Content-Type: application/json" \
+            https://service.codeant.ai/health 2>/dev/null || echo "CURL_FAILED")
+          echo "HTTP status: $HTTP_CODE"
+          head -c 200 /tmp/api_response.txt || true
+        env:
+          CODEANT_API_KEY: ${{ secrets.CODEANT_API_TOKEN }}
+
       - name: Debug Commit Info
         run: |
           echo "==== EVENT CONTEXT ===="
@@ -56,12 +66,28 @@ jobs:
           echo "==== FILES IN LAST COMMIT ===="
           git show --name-only --pretty="" HEAD
 
+            echo "==== IS MERGE COMMIT ===="
+            PARENTS=$(git log -1 --format="%P" HEAD | wc -w)
+            echo "Parent count: $PARENTS"
+            if [ "$PARENTS" -gt 1 ]; then
+              echo "HEAD is a merge commit"
+              git log --oneline HEAD~1..HEAD --first-parent || true
+            fi
+
       - name: Run CodeAnt Review
         run: |
           if [ "${GITHUB_EVENT_NAME}" = "pull_request" ] && [ -n "${GITHUB_BASE_REF}" ]; then
-            echo "Running PR review against base: ${GITHUB_BASE_REF}"
+            echo "Running PR review against base branch: ${GITHUB_BASE_REF}"
             codeant review --base "${GITHUB_BASE_REF}" 2>&1 | tee review.txt || true
           else
-            echo "Running last-commit review"
+            # For push to main: check if HEAD is a merge commit
+            PARENTS=$(git log -1 --format="%P" HEAD | wc -w)
+            if [ "$PARENTS" -gt 1 ]; then
+              # Merge commit: review everything brought in by the merge (HEAD vs first parent)
+              echo "Merge commit detected - reviewing changes vs HEAD~1"
+              codeant review --base-commit HEAD~1 2>&1 | tee review.txt || true
+            else
+              echo "Regular push - reviewing last commit"
               codeant review --last-commit 2>&1 | tee review.txt || true
             fi
+          fi