[Feature Request] Scrub ambient sensitive credentials from run_shell child environment

[cagdasyurekli]

Motivation

Currently, LocalExecutor (coworker/tools/shell.py) inherits the entire os.environ from the parent process. If a developer launches OpenWorker in a terminal session where cloud keys or personal access tokens are exported (AWS_SECRET_ACCESS_KEY, GITHUB_TOKEN, *_API_KEY), any command executed by the agent (or a build script triggered in the workspace) inherits ambient access to those secrets.

Proposed Solution

1. Introduce an environment variable filter in coworker/tools/shell.py:
   • By default, scrub known high-entropy and credential environment variable patterns (AWS_*, *_API_KEY, *_SECRET_*, *_TOKEN) from the child shell process.
   • Provide an explicit allowlist in config.toml:

     [shell]
     allowed_env = ["AWS_PROFILE", "PATH"]

2. Retain only essential system environment variables (PATH, HOME, USER, SHELL, LANG, TERM, and standard Python venv variables).

Implementation Scope & Alignment

• Scope: ~60–80 lines in coworker/tools/shell.py and coworker/config.py.
• Zero Breaking Changes: Transparent to standard developer workflows.
• Alignment: Directly reinforces OpenWorker's primary value proposition of defender-grade security.