feat: add pre-baked CI build images

- cameleer-build:1 — Maven 3.9 + Java 17 + Node.js 22 + curl/jq/procps/bc
- cameleer-docker-builder:1 — Docker 27 + git/curl/jq

Eliminates per-build tool installation across cameleer3 and cameleer3-server.

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

build/Dockerfile

@@ -0,0 +1,11 @@
+FROM maven:3.9-eclipse-temurin-17
+
+# Node.js 22 LTS via NodeSource
+RUN apt-get update && apt-get install -y ca-certificates curl gnupg \
+    && 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_22.x nodistro main" \
+       > /etc/apt/sources.list.d/nodesource.list \
+    && apt-get update && apt-get install -y nodejs procps bc jq \
+    && rm -rf /var/lib/apt/lists/*