是否支持Java方法补全

是否支持Java的方法自动补全

The issue only asks whether Java method autocompletion is supported in the WebIDE-Frontend project and names no files, tests, or entry points. First inspect the existing completion implementation and clarify the expected Java support and acceptance criteria; done should be defined by a confirmed implementation or an explicit support decision.

索引モデルが issue の本文から書いたものです。