Run repo-wide Java GUI slop sweep

[e6qu]

Summary

• run the repo-local Java GUI slop cleanup sweep and record/fix findings in BUGS.md
• fix EDT/threading, swallowed-error, stale-platform, and validation issues across GUI/protocol code
• add MinIO Testcontainers coverage for S3-compatible path-style behavior and fix S3 delete metadata state

Validation

• git diff --check
• ./gradlew :barebones-protocol-s3:test --tests dev.barebones.commander.commons.file.protocol.s3.S3MinIOIntegrationTest --stacktrace
• ./gradlew cleanTest test --stacktrace
• ./gradlew check --stacktrace