feat(channel): support Codex upstream model discovery (#6184)

* fix(i18n): clarify Go regex and field passthrough copy

* feat(channel): support Codex upstream model discovery

* Revert "fix(i18n): clarify Go regex and field passthrough copy"

This reverts commit d63d7975db3e34ff44e189112d3c15ad8c24ad88.

controller/channel_upstream_update_test.go

@@ -3,14 +3,51 @@ package controller
 import (
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 
+	"github.com/QuantumNous/new-api/common"
+	"github.com/QuantumNous/new-api/constant"
 	"github.com/QuantumNous/new-api/dto"
 	"github.com/QuantumNous/new-api/model"
 	"github.com/gin-gonic/gin"
 	"github.com/stretchr/testify/require"
 )
 
+func TestFetchModelsUsesSharedChannelFetchBehavior(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/v1/models" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		if r.Header.Get("x-api-key") != "first-key" {
+			t.Errorf("unexpected x-api-key header: %s", r.Header.Get("x-api-key"))
+		}
+		if r.Header.Get("Authorization") != "" {
+			t.Errorf("unexpected Authorization header: %s", r.Header.Get("Authorization"))
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"data":[{"id":" claude-sonnet "},{"id":"claude-sonnet"}]}`))
+	}))
+	t.Cleanup(server.Close)
+
+	body, err := common.Marshal(map[string]any{
+		"base_url": server.URL,
+		"type":     constant.ChannelTypeAnthropic,
+		"key":      "first-key\nsecond-key",
+	})
+	require.NoError(t, err)
+
+	recorder := httptest.NewRecorder()
+	ctx, _ := gin.CreateTestContext(recorder)
+	ctx.Request = httptest.NewRequest(http.MethodPost, "/api/channel/fetch_models", strings.NewReader(string(body)))
+	ctx.Request.Header.Set("Content-Type", "application/json")
+
+	FetchModels(ctx)
+
+	require.Equal(t, http.StatusOK, recorder.Code)
+	require.JSONEq(t, `{"success":true,"message":"","data":["claude-sonnet"]}`, recorder.Body.String())
+}
+
 func TestNormalizeModelNames(t *testing.T) {
 	result := normalizeModelNames([]string{
 		" gpt-4o ",