fix: improve usage URLs in status card and snapshots (#6111)

Hi OpenAI Codex team, currently "Visit chatgpt.com/codex/settings/usage
for up-to-date information on rate limits and credits" message in status
card and error messages. For now, without the "https://" prefix, the
link cannot be clicked directly from most terminals or chat interfaces.

<img width="636" height="127" alt="Screenshot 2025-11-02 at 22 47 06"
src="https://github.com/user-attachments/assets/5ea11e8b-fb74-451c-85dc-f4d492b2678b"
/>

---

The fix is intent to improve this issue:

- It makes the link clickable in terminals that support it, hence better
accessibility
- It follows standard URL formatting practices
- It maintains consistency with other links in the application (like the
existing "https://openai.com/chatgpt/pricing" links)

Thank you!

codex-rs/tui/src/status/card.rs

@@ -313,7 +313,9 @@ impl HistoryCell for StatusHistoryCell {
 
         let note_first_line = Line::from(vec![
             Span::from("Visit ").cyan(),
-            "chatgpt.com/codex/settings/usage".cyan().underlined(),
+            "https://chatgpt.com/codex/settings/usage"
+                .cyan()
+                .underlined(),
             Span::from(" for up-to-date").cyan(),
         ]);
         let note_second_line = Line::from(vec![