Feature Request: Add SkillsJars support

[iNicholasBE]

Summary

SkillsJars (Maven Central as a package manager for AI agent skills) would let users add pre-packaged skills to JavaClaw as simple Gradle dependencies.

The SkillsTool from spring-ai-agent-utils already supports classpath scanning via addSkillsResource(). The change is a single-line addition to JavaClawConfiguration.java — after which any com.skillsjars:* dependency is automatically discovered.

Inspired by @ArturSkowronski's JVM Weekly

What This Unlocks

After this change, adding any SkillsJars package is just a Gradle dependency line:

// app/build.gradle — examples
implementation 'com.skillsjars:spring-ai-community__spring-testing-skills:1.0.0'
implementation 'com.skillsjars:coreyhaines31__marketingskills__pricing-strategy:1.0.0'

Skills from those JARs appear alongside filesystem skills automatically on next startup.

[thedarshannn]

Hi @iNicholasBE! I'd like to work on this one — no one is assigned yet so I'll go ahead and start.

I've looked at JavaClawConfiguration.java and can see the fix is a one-liner: adding addSkillsResource() calls on the SkillsTool.builder() for any classpath resources matching the com.skillsjars:* pattern, alongside the existing addSkillsDirectory() call.

The SkillsTool from spring-ai-agent-utils already supports addSkillsResource() for classpath-based skill discovery, so no new dependencies are needed.

Planning to:

1. Update JavaClawConfiguration.java to scan classpath for SKILL.md resources from SkillsJars packages
2. Add a test verifying a classpath skill is discovered correctly

Let me know if there's anything specific you'd like me to keep in mind!