Support the app-server daemon on Windows (#42405)

## Why

The managed app-server daemon and automatic TUI attachment were limited to
Unix, so Windows users could not share a background server across Codex
sessions.

## What changed

- Enable daemon lifecycle commands, `codex agents` startup, and AF_UNIX daemon
  discovery on Windows.
- Require Windows daemons to start non-elevated and verify the discovered
  socket directory and peer before connecting.
- Preflight detached process support, preserve path-based environment settings,
  and keep daemon processes out of the launching project's working directory.
- Fall back to an embedded server when an implicitly discovered daemon cannot
  connect, while preserving errors for explicit remote endpoints and bypassing
  daemon reuse when `CODEX_EXEC_SERVER_URL` is set.

## Testing

Add coverage for Windows launch restrictions and socket validation, implicit
connection fallback, executor selection, daemon discovery, and the agents
dashboard startup result.

GitOrigin-RevId: e7fd63cf8690bcca8b5155266416f31f2f792aa2

codex-rs/tui/Cargo.toml

@@ -57,6 +57,7 @@ codex-shell-command = { workspace = true }
 codex-state = { workspace = true }
 codex-terminal-detection = { workspace = true }
 codex-utils-approval-presets = { workspace = true }
+codex-uds = { workspace = true }
 codex-utils-absolute-path = { workspace = true }
 codex-utils-cli = { workspace = true }
 codex-utils-elapsed = { workspace = true }