Add a link to Github releases to CHANGELOG.md

Since the file is no longer maintained, we should navigate visitors to the GitHub releases page.

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 You can install any of these versions: `npm install -g codex@version`
 
+> [!IMPORTANT]
+> This file is no longer maintained. For newer release notes, visit https://github.com/openai/codex/releases instead.
+
 ## `0.1.2505172129`
 
 ### 🪲 Bug Fixes

codex-rs/core/src/openai_model_info.rs

@@ -79,13 +79,13 @@ pub(crate) fn get_model_info(model_family: &ModelFamily) -> Option<ModelInfo> {
         }),
 
         "gpt-5" => Some(ModelInfo {
-            context_window: 200_000,
-            max_output_tokens: 100_000,
+            context_window: 400_000,
+            max_output_tokens: 128_000,
         }),
 
         _ if slug.starts_with("codex-") => Some(ModelInfo {
-            context_window: 200_000,
-            max_output_tokens: 100_000,
+            context_window: 400_000,
+            max_output_tokens: 128_000,
         }),
 
         _ => None,