refactor(windows): tidy managed-node resolver helpers

Behavior-preserving cleanups on the managed-node resolver:
- Hoist _candidate_node_command_names() out of the inner dir loop in
  find_hermes_node_executable (computed once, not per directory).
- Drop redundant os.environ.copy() at the two with_hermes_node_path(
  os.environ.copy()) sites \u2014 the helper already copies os.environ when
  called with no argument (verified env-equivalent).
- Add reciprocal keep-in-sync comments between iter_hermes_node_dirs()
  (hermes_constants.py) and hermesManagedNodePathEntries() (electron
  main.cjs), which mirror the same platform-ordering rule across the
  Python/Node boundary.

apps/desktop/electron/main.cjs

@@ -270,6 +270,9 @@ function resolveHermesHome() {
 const HERMES_HOME = resolveHermesHome()
 
 function hermesManagedNodePathEntries() {
+  // NOTE: keep this ordering in sync with iter_hermes_node_dirs() in
+  // hermes_constants.py — this Node main process cannot import the Python
+  // module, so the platform-ordering rule is mirrored here.
   const root = path.join(HERMES_HOME, 'node')
   const bin = path.join(root, 'bin')
   const entries = IS_WINDOWS ? [root, bin] : [bin, root]