fix(code-runtime): preserve native temp setup and preview activation

packages/code-runtime/code-runtime-node/README.md

@@ -83,7 +83,7 @@ The host owns policy, deadlines, binding lookup and process cleanup. The child o
 
 ### Launch and control
 
-The host strips erasable types, resolves the executable and bootstrap in the configured execution world, wraps the argv through `ctx.sandbox`, and spawns through `ctx.subprocess`. After adopting the inherited control channel, the child retains only executable-search and Windows system paths in its OS environment and replaces the program-visible `process.env` with an empty dictionary. The retained native paths keep nested Windows process creation functional. The heap limit uses Node argv or a provider-created `NODE_OPTIONS` value for packaged executables; ambient loader and inspector flags are discarded.
+The host strips erasable types, resolves the executable and bootstrap in the configured execution world, wraps the argv through `ctx.sandbox`, and spawns through `ctx.subprocess`. After adopting the inherited control channel, the child retains only executable-search, Windows system, and temporary paths in its OS environment and replaces the program-visible `process.env` with an empty dictionary. Windows ACL setup receives the parent's distinct `TEMP` and `TMP` values for shared grant locks, then replaces both with its private directory before starting the program. These native paths keep nested process creation and native temporary-file APIs functional. The heap limit uses Node argv or a provider-created `NODE_OPTIONS` value for packaged executables; ambient loader and inspector flags are discarded.
 
 Length-framed JSON travels separately from stdout/stderr. The host bounds frames and queued writes, validates call identity and declared binding names before dispatch, and refuses invalid traffic. Output capture meters serialized logs plus the completion or diagnostic; fixed result-envelope fields and sandbox metadata are outside that ledger.