Document Copilot agent install step for local builds

[Copilot]

Local Maven packaging fails from a fresh clone because com.microsoft.copilot.eclipse.core/build.properties includes copilot-agent/dist/, but that directory is generated by the Copilot agent npm install step. CI already performs this setup before running Maven.

• Build prerequisites

  • Adds Node.js 22.13+ with npm to the documented prerequisites.
  • Aligns the Java prerequisite with CI’s Temurin 17 setup.

• Local build flow

  • Documents the required Copilot agent install step before Maven packaging:

    cd com.microsoft.copilot.eclipse.core/copilot-agent
    npm i -f
    cd ../..
    ./mvnw clean package

• Contributor validation flow

  • Adds the same agent install step before the documented checkstyle, verify, and test commands.
  • Notes that npm i -f runs the agent postinstall script to populate copilot-agent/dist/ and platform-specific agent bundles required by Tycho.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• www.eclipse.org
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -classpath /home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1/boot/plexus-classworlds-2.8.0.jar -Dclassworlds.conf=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1/bin/m2.conf -Dmaven.home=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1 -Dlibrary.jansi.path=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/copilot-for-eclipse/copilot-for-eclipse org.codehaus.plexus.classworlds.launcher.Launcher clean package --batch-mode (dns block)
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -classpath /home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1/boot/plexus-classworlds-2.8.0.jar -Dclassworlds.conf=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1/bin/m2.conf -Dmaven.home=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1 -Dlibrary.jansi.path=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/copilot-for-eclipse/copilot-for-eclipse org.codehaus.plexus.classworlds.launcher.Launcher clean verify --batch-mode (dns block)
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -classpath /home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1/boot/plexus-classworlds-2.8.0.jar -Dclassworlds.conf=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1/bin/m2.conf -Dmaven.home=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1 -Dlibrary.jansi.path=/home/REDACTED/.m2/wrapper/dists/apache-maven-3.9.9/3477a4f1/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/copilot-for-eclipse/copilot-for-eclipse org.codehaus.plexus.classworlds.launcher.Launcher clean verify --batch-mode -Dorg.eclipse.wildwebdeveloper.nodeJSLocation=/home/REDACTED/.npm/_npx/1bd81ab945294a66/node_modules/node/bin/node (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[Copilot]

Pull request overview

This PR updates contributor documentation to prevent local Maven/Tycho builds from failing on fresh clones by documenting the required Copilot agent npm install step (which generates copilot-agent/dist/ and populates the platform agent fragments).

Changes:

• Updates prerequisites to include Node.js/npm and align Java with CI’s Temurin 17.
• Documents running npm i -f in com.microsoft.copilot.eclipse.core/copilot-agent before Maven build commands.
• Adds brief rationale explaining that npm postinstall populates copilot-agent/dist/ and agent bundles needed by Tycho.