refactor: simplify context_management compatibility handling

internal/translator/codex/openai/responses/codex_openai-responses_request.go

@@ -2,7 +2,6 @@ package responses
 
 import (
 	"fmt"
-	"strings"
 
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
@@ -47,32 +46,12 @@ func ConvertOpenAIResponsesRequestToCodex(modelName string, inputRawJSON []byte,
 //
 // Compatibility strategy:
 // 1) Remove context_management before forwarding to Codex upstream.
-// 2) Remove truncation as Codex upstream currently rejects it as unsupported.
 func applyResponsesCompactionCompatibility(rawJSON []byte) []byte {
-	contextManagement := gjson.GetBytes(rawJSON, "context_management")
+	if !gjson.GetBytes(rawJSON, "context_management").Exists() {
-	if !contextManagement.Exists() {
 		return rawJSON
 	}
 
-	hasCompactionRule := false
-	switch {
-	case contextManagement.IsArray():
-		for _, item := range contextManagement.Array() {
-			if strings.EqualFold(item.Get("type").String(), "compaction") {
-				hasCompactionRule = true
-				break
-			}
-		}
-	case contextManagement.IsObject():
-		hasCompactionRule = strings.EqualFold(contextManagement.Get("type").String(), "compaction")
-	}
-
-	if hasCompactionRule {
-		// no-op marker: compaction hint detected and consumed for compatibility.
-	}
-
 	rawJSON, _ = sjson.DeleteBytes(rawJSON, "context_management")
-	rawJSON, _ = sjson.DeleteBytes(rawJSON, "truncation")
 	return rawJSON
 }