GHSA-fg23-3346-88f5: Langroid: Path traversal in the file tools allows read/write outside configured current directory

Langroid's ReadFileTool and WriteFileTool have a path traversal vulnerability (a security flaw where attackers use sequences like ../ to access files outside intended boundaries) because they only change the working directory but don't validate that file paths stay within the configured curr_dir (current directory) boundary. An attacker can use paths like ../secret.txt to read or write files outside the intended sandbox directory, potentially compromising applications that rely on curr_dir to restrict file access.