Summary

• add an exec-server envPolicy field; when present, the server starts from its own process env and applies the shell environment policy there
• keep env as the exact environment for local/embedded starts, but make it an overlay for remote unified-exec starts
• move the shell-environment-policy builder into codex-config so Core and exec-server share the inherit/filter/set/include behavior
• overlay only runtime/sandbox/network deltas from Core onto the exec-server-derived env

Why

Remote unified exec was materializing the shell env inside Core and forwarding the whole map to exec-server, so remote processes could inherit the orchestrator machine's HOME, PATH, etc. This keeps the base env on the executor while preserving Core-owned runtime additions like CODEX_THREAD_ID, unified-exec defaults, network proxy env, and sandbox marker env.

Validation

• just fmt
• git diff --check
• cargo test -p codex-exec-server --lib
• cargo test -p codex-core --lib unified_exec::process_manager::tests
• cargo test -p codex-core --lib exec_env::tests
• cargo test -p codex-core --lib exec_env_tests (compile-only; filter matched 0 tests)
• cargo test -p codex-config --lib shell_environment (compile-only; filter matched 0 tests)
• just bazel-lock-update

Known local validation issue

• just bazel-lock-check is not runnable in this checkout: it invokes ./scripts/check-module-bazel-lock.sh, which is missing.