🛡️ Sentinel: [CRITICAL] Fix Path Traversal via Symbolic Links

[georgi]

This PR fixes a security vulnerability in src/nodetool/io/path_utils.py where os.path.abspath was being used to evaluate whether a requested file path was within the designated workspace_dir.

🚨 Severity: CRITICAL
💡 Vulnerability: Symlink-based Path Traversal
🎯 Impact: If a malicious user or external process were able to create a symbolic link within their workspace that points to a directory outside of the workspace (e.g., / or /etc), os.path.abspath would not resolve the symlink. This allowed requests traversing the symlink to pass the commonpath boundary check, granting arbitrary read/write access to the host filesystem.
🔧 Fix: Replaced os.path.abspath with os.path.realpath for both the workspace root and the target path. os.path.realpath fully resolves all symbolic links before evaluating the boundaries, correctly denying access to outside files.
✅ Verification: A test case test_resolve_workspace_path_with_symlink_traversal_attack was added to tests/common/test_path_utils.py to ensure traversing an outside symlink correctly throws a ValueError. The fix has been verified and passes tests.

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PR created automatically by Jules for task 12244774363765268999 started by @georgi

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