- Add DEFAULT_ENV_WHITELIST constant with safe env vars (AGENT_ID, TASK_ID,
NODE_ENV, LOG_LEVEL, TZ, MOSAIC_* vars, etc.)
- Implement filterEnvVars() to separate allowed/filtered vars
- Log security warning when non-whitelisted vars are filtered
- Support custom whitelist via orchestrator.sandbox.envWhitelist config
- Add comprehensive tests for whitelist functionality (39 tests passing)
Prevents accidental leakage of secrets like API keys, database credentials,
AWS secrets, etc. to Docker containers.
Refs #338
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>