fix(tui): wrap feedback thread link in backticks

After feedback upload completes for OpenAI employees, we print a
`go/codex-feedback/<thread_id>` snippet to share in #codex-feedback.

Wrap the snippet in backticks so it's ready to paste into Slack as inline
code and is visually distinct from surrounding text.

codex-rs/tui/src/bottom_pane/feedback_view.rs

@@ -129,7 +129,7 @@ impl FeedbackNoteView {
                             Line::from("  Share this and add some info about your problem:"),
                             Line::from(vec![
                                 "    ".into(),
-                                format!("go/codex-feedback/{thread_id}").bold(),
+                                format!("`go/codex-feedback/{thread_id}`").bold(),
                             ]),
                         ]);
                     }