build: add Node.js 24 to java-builder for actions/checkout support

Gitea Actions checkout@v6 requires Node.js to run. Added Node 24
via NodeSource apt repo (~30MB).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ci/java-builder/Dockerfile

@@ -18,11 +18,21 @@ ARG OWASP_DC_VERSION=12.1.0
 # ─────────────────────────────────────────────────────────────────────
 # System dependencies
 # ─────────────────────────────────────────────────────────────────────
+ARG NODE_MAJOR=24
+
 RUN apt-get update && apt-get install -y --no-install-recommends \
+        ca-certificates \
         curl \
         git \
+        gnupg \
         jq \
         unzip \
+    && mkdir -p /etc/apt/keyrings \
+    && curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key \
+        | gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg \
+    && echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_${NODE_MAJOR}.x nodistro main" \
+        > /etc/apt/sources.list.d/nodesource.list \
+    && apt-get update && apt-get install -y --no-install-recommends nodejs \
     && rm -rf /var/lib/apt/lists/*
 
 # ─────────────────────────────────────────────────────────────────────
@@ -62,4 +72,4 @@ RUN curl -fsSL "https://github.com/oras-project/oras/releases/download/v${ORAS_V
 WORKDIR /workspace
 
 # Verify installation
-RUN java -version && mvn -version && oras version && jq --version
+RUN java -version && mvn -version && node --version && oras version && jq --version