fix: include cameleer3-log-appender.jar in runtime base image

The log appender JAR was missing from the cameleer-runtime-base Docker
image, causing agent log forwarding to silently fail with "No supported
logging framework found, log forwarding disabled". This meant only
container stdout logs (source=container) were captured — no application
or agent logs reached ClickHouse.

CI now downloads the appender JAR from the Maven registry alongside the
agent JAR, and the Dockerfile COPYs it to /app/cameleer3-log-appender.jar
where the server's Docker entrypoint expects it (-Dloader.path for
Spring Boot, -cp for plain Java).

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

docker/runtime-base/Dockerfile

@@ -1,9 +1,9 @@
 FROM eclipse-temurin:21-jre-alpine
 WORKDIR /app
 
-# Agent JAR is copied during CI build from Gitea Maven registry
-# ARG AGENT_JAR=cameleer3-agent-1.0-SNAPSHOT-shaded.jar
+# Agent JAR and log appender JAR are copied during CI build from Gitea Maven registry
 COPY agent.jar /app/agent.jar
+COPY cameleer3-log-appender.jar /app/cameleer3-log-appender.jar
 
 ENTRYPOINT exec java \
   -Dcameleer.export.type=${CAMELEER_EXPORT_TYPE:-HTTP} \