envd: Host file disclosure through requirements path traversal and TOCTOU

envd provides reproducible development environments for humans and agents. In versions starting with 0.3.38 and before 1.3.6, insufficient containment of host-side requirements-file reads in  install.python_packages(requirements=...)  could allow access to files outside the build context. An attacker able to influence build input could cause file contents interpreted as dependency entries to appear in debug logs or build-step metadata, subject to the envd process’s permissions. Exploitation in version 1.3.5 additionally requires concurrent modification of relevant filesystem paths. This issue is fixed in version 1.3.6.