fix: default project root to workspace instead of user.dir in LocalFilesystemSpec

[waterWang]

Fixes #2065

Problem

LocalFilesystemSpec.toFilesystem() falls back to System.getProperty("user.dir") when project is not explicitly set. In non-CLI scenarios (web applications, embedded agents), this exposes the JVM's working directory as the read-only lower layer of the OverlayFilesystem, allowing the agent to read source code, config files, and other sensitive files it should not have access to.

Root cause

Paths.get(System.getProperty("user.dir")) in toFilesystem() — the JVM working directory is unrelated to the agent's intended workspace in non-CLI deployments.

Fix

• Default effectiveProject to workspace (the agent workspace root, same as the upper layer) instead of System.getProperty("user.dir") when project is null
• Remove unused import java.nio.file.Paths
• Update all Javadoc references to reflect the new default

CLI users who need their project directory as the lower layer should continue to call .project(Path) explicitly.

[gemini-code-assist]

Caution

The consumer version of Gemini Code Assist on GitHub has been sunset. All code review activity has officially ceased.

[oss-maintainer]

Code Review — PR #2466

fix: default project root to workspace instead of user.dir in LocalFilesystemSpec

Fixes #2065

Summary

Changes the default fallback for LocalFilesystemSpec.toFilesystem() from System.getProperty("user.dir") (JVM working directory) to the agent workspace directory, preventing unintended file system exposure in non-CLI deployments.

Analysis

This is a clean, minimal security fix:

• Paths.get(System.getProperty("user.dir")) → workspace
• Removes unused import java.nio.file.Paths
• Updates all Javadoc references to match

The change correctly addresses the root cause: in web applications or embedded agents, the JVM working directory is unrelated to the agent's intended workspace and could expose sensitive files (source code, configs) through the read-only lower layer of OverlayFilesystem.

Observations

• ✅ Correct security fix — eliminates unintended file system exposure
• ✅ Minimal diff (4 additions, 5 deletions) — no unnecessary changes
• ✅ Javadoc updated consistently
• ✅ CLI users can still use .project(Path) explicitly for the old behavior
• ❌ CI failed — Spotless formatting in LocalFilesystemSpec.java. The diff shows a trailing blank line issue. Run mvn spotless:apply to fix.

Required Action

@waterWang Please run mvn spotless:apply in the agentscope-harness module and push the fix.

Verdict

Request Changes — logic is correct and important security fix, but Spotless formatting must be fixed before merge.