fix: hide empty non-Java folder ancestors

[wenyt (wenytang-ms)]

Summary

• hide physical non-Java folder ancestors when their entire subtree is already represented by Java model/package-root nodes
• keep real non-Java resources visible through their Java resource root
• add a Maven regression fixture and project-view test for the empty src/main hierarchy

This fixes the empty physical src/main tree reported when Show Non-Java Resources is enabled. It intentionally does not change the visibility policy for Maven target or other build-output folders.

Root cause

java.getPackageData combines Java classpath roots with IJavaProject.getNonJavaResources(). A physical ancestor such as src could therefore be emitted as a normal folder even though src/main/java and src/main/resources were already represented as package roots. Expanding the physical folder filtered those Java elements and left an empty hierarchy.

Testing

• JDTLS extension build and checkstyle
• npm run compile
• npm run tslint
• Maven Project View Tests: 15 passing
• AutoTest java-dep-view-modes: 36/36 passing with the fix
• Pre-fix A/B: 35/36 passing; only verify-empty-physical-src-hidden fails

Fixes #1062
Related to #1044

UI verification

The Maven resource root and application.yml remain visible, while the duplicate physical src hierarchy is absent.

Before	After
The extra physical src folder is shown below .vscode.	The extra src folder is removed; target follows .vscode.

[Copilot]

Pull request overview

Fixes duplicate empty physical source ancestors in the Java Projects view while preserving non-Java resources.

Changes:

• Filters redundant source-root ancestors in JDTLS.
• Adds Maven fixture and regression coverage.
• Extends AutoTest coverage for resource visibility.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
ResourceSet.java	Filters physical source ancestors.
projectView.test.ts (simple)	Updates expected project children.
projectView.test.ts (Maven)	Tests resource-root visibility.
application.yml	Adds a non-Java resource fixture.
java-dep-view-modes.yaml	Adds E2E regression checks.

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[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.