Workspace lints and disallow unwrap (#855)

Sets submodules to use workspace lints. Added denying unwrap as a
workspace level lint, which found a couple of cases where we could have
propagated errors. Also manually labeled ones that were fine by my eye.

codex-rs/tui/src/lib.rs

@@ -2,7 +2,6 @@
 // The standalone `codex-tui` binary prints a short help message before the
 // alternate‑screen mode starts; that file opts‑out locally via `allow`.
 #![deny(clippy::print_stdout, clippy::print_stderr)]
-
 use app::App;
 use codex_core::config::Config;
 use codex_core::config::ConfigOverrides;