## Why
Windows unified-exec TTY input did not behave like the non-Windows PTY
path. ConPTY sessions could receive the wrong line ending or mishandle
backspace, especially when sending input to a foreground program through
PowerShell or cmd. The local, legacy restricted, and elevated paths also
handled this normalization separately.
## What changed
- share one stateful Windows TTY input normalizer across local, legacy
restricted, and elevated runner paths
- translate LF and split CRLF into one Windows terminal Enter, encode
backspace as DEL, and preserve UTF-8 and control bytes such as Ctrl-C
- add Windows integration coverage for Unicode input, backspace, Enter,
and PowerShell foreground-child Ctrl-C behavior
## Validation
- `just test -p codex-utils-pty` (13 tests passed; the Unicode
integration test retried once)
- the Unicode integration test passed five consecutive runs with retries
disabled
- integration coverage sends `cafeé 漢字` through cmd and PowerShell and
verifies that Ctrl-C interrupts a running PowerShell foreground child
iceweasel-oai