[Console] EnvInitializer skips Maven local repo creation when directory is missing

[shangeyao]

Problem

EnvInitializer.createMvnLocalRepoDir() only calls mkdirs when the Maven local repository path already exists, so a missing directory is never created on first startup.

Expected

Create the Maven local repository directory when it does not exist, consistent with other workspace directories initialized by EnvInitializer.

Proposed fix

Use FsOperator.lfs().mkdirsIfNotExists(localMavenRepo) instead of the inverted exists check.

[shangeyao]

Closing because related PR #4379 was closed without merge. Console frontend is being refactored; this work is deferred.