* Initial plan
* docs: replace HelloWorldApp references with java --version in README and advanced-usage
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Closes#990
Maven build extensions declared in `.mvn/extensions.xml` can introduce
additional plugin dependencies (e.g. lifecycle participants, custom
packaging types). Including this file in the cache key hash ensures that
changes to extensions — which affect what plugin JARs Maven downloads —
properly invalidate the cache, preventing stale caches from missing
newly-required plugin dependencies.
Changes:
- src/cache.ts: add `**/.mvn/extensions.xml` to Maven pattern array
- __tests__/cache.test.ts: update pattern expectations; add new test
- README.md: document the new file in the Maven cache key hash list
