[codex] Support remote exec cwd in TUI startup (#17142)

When running with remote executor the cwd is the remote path. Today we
check for existence of a local directory on startup and attempt to load
config from it.

For remote executors don't do that.

codex-rs/Cargo.lock

@@ -1505,6 +1505,7 @@ dependencies = [
  "codex-app-server-protocol",
  "codex-arg0",
  "codex-core",
+ "codex-exec-server",
  "codex-feedback",
  "codex-protocol",
  "futures",