Support multi-environment apply_patch selection (#21617)

## Summary
- add multi-environment apply_patch routing for both freeform and
function-call tool flows
- parse and reconcile the optional environment selector in the main
apply_patch parser, then verify against the selected environment in the
handler
- carry environment_id through runtime and approval surfaces so
remote-targeted patches stay explicit end to end

## Testing
- just fmt
- remote exec-server e2e: `cargo test -p codex-core --test all
apply_patch_multi_environment_uses_remote_executor -- --nocapture` on
dev via `scripts/test-remote-env.sh`

---------

Co-authored-by: Codex <noreply@openai.com>

codex-rs/core/src/apply_patch.rs

@@ -40,7 +40,7 @@ pub(crate) async fn apply_patch(
         turn_context.approval_policy.value(),
         &turn_context.permission_profile(),
         file_system_sandbox_policy,
-        &turn_context.cwd,
+        &action.cwd,
         turn_context.windows_sandbox_level,
     ) {
         SafetyCheck::AutoApprove {