Java quickstart docs: javac/java commands don't work without classpath setup, version 2.20.0 doesn't exist

[JustinMifkovich]

Problem

The Java tab on the Get Started page has two issues that prevent the quickstart from working at all.

1. javac/java commands are missing classpath setup

The docs tell users to run:

```bash
javac QuickStart.java
java QuickStart
```

This fails immediately because QuickStart.java imports com.anthropic.* JARs that javac has no knowledge of. Unlike the Python tab (which shows pip install anthropic) and the TypeScript tab (which shows npm install @anthropic-ai/sdk), the Java tab skips the dependency resolution step entirely.

The correct approach with Maven is:

```bash
mvn compile exec:java -Dexec.mainClass=QuickStart
```

Or the raw javac/java approach would require manually assembling all transitive JARs and passing them via -cp, which is impractical.

2. Version 2.20.0 does not exist on Maven Central

The Maven/Gradle snippets reference version 2.20.0, which returns a 404 from Maven Central. The latest available version as of this writing is 2.26.0.

Suggested fix

• Update the version number in the Maven/Gradle snippets to the current release
• Replace the javac/java run step with Maven (or Gradle) instructions, consistent with how the Python and TypeScript tabs handle dependency installation