fix(runner): 修复转存后残留二进制误判

统一结果二进制探测与上传规则，避免将 thinking_bytes 等上游元数据误判为待转存媒体，同时保留显式媒体字段和签名识别。\n\n补充不含原始内容的安全诊断，并兼容对象存储前缀旧字段；修正真实 OSS 验收脚本使用的正式字段。\n\n验证：Go 全量测试、go vet、迁移安全检查、真实 Gemini 上游响应及阿里云 OSS 转存均通过。

apps/api/internal/runner/upload.go

@@ -306,9 +306,17 @@ func (s *Service) finalizeGeneratedAssets(
 	if !TaskResultHasInlineBinary(next) {
 		return next, nil
 	}
+	diagnostics := taskResultInlineBinaryDiagnostics(next)
+	if s.logger != nil {
+		s.logger.Error("generated result still contains inline binary after object storage materialization",
+			"taskID", taskID,
+			"remainingInlineBinary", diagnostics,
+		)
+	}
 	return nil, &clients.ClientError{
 		Code:       "storage_write_failed",
 		Message:    "generated binary result could not be written to object storage",
+		Details:    map[string]any{"scope": "gateway_result_storage", "remainingInlineBinary": diagnostics},
 		StatusCode: http.StatusServiceUnavailable,
 		Retryable:  true,
 	}
@@ -417,24 +425,19 @@ func (s *Service) uploadGeneratedBinaryValue(ctx context.Context, taskID string,
 }
 
 func generatedRawInlineMediaAsset(key string, value string, siblings map[string]any, taskKind string) (*generatedInlineAsset, bool) {
-	raw := strings.TrimSpace(value)
-	if raw == "" {
-		return nil, false
-	}
-	keyLooksLikeMediaPayload := generatedRawDataMediaPayloadKey(key)
-	contentType := firstNonEmptyString(mediaContentTypeFromItem(siblings), defaultContentTypeForRawMediaKey(key))
-	if !keyLooksLikeMediaPayload && !generatedContentTypeIsMedia(contentType) && !generatedContentTypeIsDocument(contentType) &&
-		!strings.HasPrefix(strings.ToLower(raw), "data:") && len(raw) < localBinaryGenericBase64MinLength {
-		return nil, false
-	}
-	payload, payloadContentType, ok, err := inlineMediaPayload(raw, keyLooksLikeMediaPayload)
-	if err != nil || !ok || len(payload) == 0 {
-		return nil, false
-	}
-	contentType = firstNonEmptyString(payloadContentType, contentType, detectGeneratedAssetContentType(payload))
-	if !generatedContentTypeIsMedia(contentType) && !generatedContentTypeIsDocument(contentType) {
-		return nil, false
+	payload, contentType, _, ok := localBinaryStringBytes(key, value, siblings)
+	if !ok {
+		contentType = firstNonEmptyString(mediaContentTypeFromItem(siblings), defaultContentTypeForRawMediaKey(key))
+		if !generatedContentTypeIsMedia(contentType) && !generatedContentTypeIsDocument(contentType) {
+			return nil, false
+		}
+		var err error
+		payload, _, ok, err = inlineMediaPayload(value, false)
+		if err != nil || !ok || len(payload) == 0 {
+			return nil, false
+		}
 	}
+	contentType = firstNonEmptyString(contentType, detectGeneratedAssetContentType(payload))
 	kind := mediaKindForAsset(taskKind, siblings, key, contentType)
 	return &generatedInlineAsset{
 		Bytes:       payload,