refactor: unify empty-output retry logic into shared completionruntime package and normalize protocol adapter boundary.

internal/completionruntime/stream_retry_test.go

@@ -0,0 +1,62 @@
+package completionruntime
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+
+	"ds2api/internal/auth"
+	"ds2api/internal/httpapi/openai/shared"
+)
+
+func TestExecuteStreamWithRetryUsesSharedRetryPayloadAndUsagePrompt(t *testing.T) {
+	ds := &fakeDeepSeekCaller{responses: []*http.Response{
+		sseHTTPResponse(http.StatusOK, `data: {"p":"response/content","v":"ok"}`),
+	}}
+	initial := sseHTTPResponse(http.StatusOK, `data: {"response_message_id":77,"p":"response/thinking_content","v":"plan"}`)
+	payload := map[string]any{"prompt": "original prompt"}
+	attemptsSeen := 0
+	retryPrompt := ""
+
+	ExecuteStreamWithRetry(context.Background(), ds, &auth.RequestAuth{}, initial, payload, "pow", StreamRetryOptions{
+		Surface:      "test.stream",
+		Stream:       true,
+		RetryEnabled: true,
+		UsagePrompt:  "original prompt",
+	}, StreamRetryHooks{
+		ConsumeAttempt: func(resp *http.Response, allowDeferEmpty bool) (bool, bool) {
+			defer func() {
+				if err := resp.Body.Close(); err != nil {
+					t.Fatalf("close failed: %v", err)
+				}
+			}()
+			_, _ = io.ReadAll(resp.Body)
+			attemptsSeen++
+			return attemptsSeen == 2, attemptsSeen == 1 && allowDeferEmpty
+		},
+		ParentMessageID: func() int {
+			return 77
+		},
+		OnRetryPrompt: func(prompt string) {
+			retryPrompt = prompt
+		},
+	})
+
+	if attemptsSeen != 2 {
+		t.Fatalf("expected two stream attempts, got %d", attemptsSeen)
+	}
+	if len(ds.payloads) != 1 {
+		t.Fatalf("expected one retry completion call, got %d", len(ds.payloads))
+	}
+	if got := ds.payloads[0]["parent_message_id"]; got != 77 {
+		t.Fatalf("retry parent_message_id mismatch: %#v", got)
+	}
+	if prompt, _ := ds.payloads[0]["prompt"].(string); !strings.Contains(prompt, shared.EmptyOutputRetrySuffix) {
+		t.Fatalf("expected retry suffix in payload prompt, got %q", prompt)
+	}
+	if !strings.Contains(retryPrompt, shared.EmptyOutputRetrySuffix) {
+		t.Fatalf("expected retry suffix in usage prompt, got %q", retryPrompt)
+	}
+}