Improve Codex Chat reasoning conversion

- Convert Chat reasoning_content and reasoning fields into Responses reasoning output items.
- Emit Responses reasoning summary SSE events for streamed Chat reasoning deltas.
- Preserve output ordering when reasoning, text, and tool calls are streamed together.
- Add regression coverage for data-only Chat SSE errors, multiple tool calls, and compact routing.

src-tauri/src/proxy/forwarder.rs

@@ -2793,6 +2793,15 @@ mod tests {
         assert_eq!(passthrough_query.as_deref(), Some("foo=bar"));
     }
 
+    #[test]
+    fn rewrite_codex_responses_compact_endpoint_to_chat_preserves_query() {
+        let (endpoint, passthrough_query) =
+            rewrite_codex_responses_endpoint_to_chat("/v1/responses/compact?foo=bar");
+
+        assert_eq!(endpoint, "/chat/completions?foo=bar");
+        assert_eq!(passthrough_query.as_deref(), Some("foo=bar"));
+    }
+
     #[test]
     fn rewrite_claude_transform_endpoint_uses_copilot_path() {
         let (endpoint, passthrough_query) = rewrite_claude_transform_endpoint(