feat(node): Add tracePropagation option to httpIntegration and nativeNodeFetchIntegration

docs/platforms/javascript/common/configuration/integrations/http.mdx

@@ -87,6 +87,12 @@ The callback function receives two arguments:
 - `url`: The full URL of the incoming request, including the protocol, host, port, path and query string. For example: `https://example.com/users?name=John`.
 - `request`: An object of type `RequestOptions` containing the incoming request's options. You can use this to filter on properties like the request method or headers.
 
+### `tracePropagation`
+
+_Type: `boolean`_ (Defaults to `true`)
+
+Whether to inject trace propagation headers (`sentry-trace`, `baggage`, `traceparent`) into outgoing HTTP requests. When set to `false`, Sentry will not inject any trace propagation headers but will still create breadcrumbs (if `breadcrumbs` is enabled). This is useful when `skipOpenTelemetrySetup: true` is configured and your external OpenTelemetry setup already handles trace propagation, to avoid duplicate headers.
+
 ### `ignoreOutgoingRequests`
 
 _Type: `(url: string, request: RequestOptions) => boolean`_

docs/platforms/javascript/common/configuration/integrations/nodefetch.mdx

@@ -55,6 +55,12 @@ _Type: `boolean`_
 
 If set to false, no breadcrumbs will be captured.
 
+### `tracePropagation`
+
+_Type: `boolean`_ (Defaults to `true`)
+
+Whether to inject trace propagation headers (`sentry-trace`, `baggage`, `traceparent`) into outgoing fetch requests. When set to `false`, Sentry will not inject any trace propagation headers but will still create breadcrumbs (if `breadcrumbs` is enabled). This is useful when `skipOpenTelemetrySetup: true` is configured and your external OpenTelemetry setup already handles trace propagation, to avoid duplicate headers.
+
 ### `ignoreOutgoingRequests`
 
 _Type: `(url: string) => boolean`_

docs/platforms/javascript/common/opentelemetry/custom-setup.mdx

@@ -104,14 +104,14 @@ If you want to add your own http/node-fetch instrumentation, you have to follow
 
 <AvailableSince version="8.35.0" />
 
-You can add your own `@opentelemetry/instrumentation-http` instance in your OpenTelemetry setup. However, in this case, you need to disable span creation in Sentry's `httpIntegration`:
+You can add your own `@opentelemetry/instrumentation-http` instance in your OpenTelemetry setup. However, in this case, you need to disable span creation in Sentry's `httpIntegration`. You can also set `tracePropagation: false` to prevent Sentry from injecting trace headers, letting your OpenTelemetry setup handle propagation instead:
 
 <PlatformSection notSupported={["javascript.bun"]}>
   ```javascript
   const sentryClient = Sentry.init({
   dsn: "___DSN___",
   skipOpenTelemetrySetup: true,
-  integrations: [Sentry.httpIntegration({ spans: false })],
+  integrations: [Sentry.httpIntegration({ spans: false, tracePropagation: false })],
 });
   ```
 </PlatformSection>
@@ -134,6 +134,16 @@ It's important that `httpIntegration` is still registered this way to ensure tha
 
 If tracing is disabled, the Node Fetch instrumentation will not emit any spans. In this scenario, it will only inject sentry-specific trace propagation headers. You are free to add your own Node Fetch instrumentation on top of this which may emit spans as you like.
 
+If your OpenTelemetry setup already handles trace propagation for fetch requests, you can set `tracePropagation: false` to prevent Sentry from injecting duplicate trace headers:
+
+```javascript
+const sentryClient = Sentry.init({
+  dsn: "___DSN___",
+  skipOpenTelemetrySetup: true,
+  integrations: [Sentry.nativeNodeFetchIntegration({ tracePropagation: false })],
+});
+```
+
 ## Using a Custom Sampler
 
 While you can use your own sampler, we recommend that you use the `SentrySampler`. This will ensure that the correct subset of traces will be sent to Sentry, based on your `tracesSampleRate`. It will also ensure that all other Sentry features like trace propagation work as expected. If you do need to use your own sampler, make sure to wrap your `SamplingResult` with our `wrapSamplingDecision` method like in the example below: