CI: drop upload-artifact — unsupported on this Gitea instance

Run 2 built clean (311 tests, BUILD SUCCESS, Maven 3.6.3 on Java 25.0.4 —
JAVA_HOME from setup-java correctly beat the JRE apt pulled in) but the job
still went red on the artifact step:

  GHESNotSupportedError: @actions/artifact v2.0.0+, upload-artifact@v4+ and
  download-artifact@v4+ are not currently supported on GHES.

Gitea Actions presents as GHES, so v4 artifact upload cannot work here. The
artifact was unretrievable regardless, so replace it with a failure-only step
that cats the failing surefire .txt reports into the job log, where they are
readable. Guarded with 'exit 0' so the dump itself can never mask the real
failure.

.gitea/workflows/ci.yml

@@ -39,10 +39,17 @@ jobs:
         # that runs does so against the fake UDS herdr and fake ccs/claude stubs.
         run: mvn -B clean install
 
-      - name: Publish test report
-        if: always()
-        uses: actions/upload-artifact@v4
-        with:
-          name: surefire-reports
-          path: bridged/target/surefire-reports/
-          if-no-files-found: warn
+      # Deliberately NOT actions/upload-artifact: this Gitea instance presents as GHES, and
+      # @actions/artifact v2+ (i.e. upload-artifact@v4) refuses to run there —
+      # "GHESNotSupportedError ... not currently supported on GHES", which red-Xes an otherwise
+      # green build. Since the artifact could not be retrieved anyway, dump the failing tests into
+      # the log instead, where they are actually readable.
+      - name: Failing test output
+        if: failure()
+        working-directory: bridged
+        run: |
+          for f in target/surefire-reports/*.txt; do
+            [ -f "$f" ] || continue
+            grep -qE "Failures: [1-9]|Errors: [1-9]" "$f" && { echo "===== $f ====="; cat "$f"; }
+          done
+          exit 0