feat: add support for file_opener option in Rust, similiar to #911 (#957)

This ports the enhancement introduced in
https://github.com/openai/codex/pull/911 (and the fixes in
https://github.com/openai/codex/pull/919) for the TypeScript CLI to the
Rust one.

codex-rs/tui/src/lib.rs

@@ -19,6 +19,7 @@ mod app_event;
 mod app_event_sender;
 mod bottom_pane;
 mod chatwidget;
+mod citation_regex;
 mod cli;
 mod conversation_history_widget;
 mod exec_command;