Fix documentation issues from course review

Regenerate slides PDF for LangChain4j 1.10.0

Upgrade LangChain4j from 1.7.1 to 1.10.0

Remove 'What's New in 1.7.1?' slides from main branch

Update Java toolchain configuration and remove spotless ratcheting

Update slides PDF with Lab 6.6 content

Add Lab 6.6 Multi-Agent Systems slides

Add Lab 6.6: Multi-Agent Systems (AgenticServices)

Remove npm package files from repository

Replace slides with comprehensive training deck and export PDF

Update to GPT-5 models and remove temperature settings

Fix slides 21 and 22 formatting issues

Refactor long slides into shorter, focused content

Upgrade to LangChain4j 1.7.1 with comprehensive updates

Apply spotless plugin configuration from solutions branch