docs(unreal): Add experimental native backend support for Windows and Linux

docs/platforms/unreal/configuration/native-backend/index.mdx

@@ -0,0 +1,50 @@
+---
+title: Native Backend
+sidebar_order: 12
+description: "Learn how to use the experimental native crash backend as an alternative to Crashpad on Windows and Linux."
+---
+
+The Sentry Unreal SDK uses Crashpad as the default crash reporting backend on Windows and Linux. As an alternative, you can enable the experimental native backend, which uses a different crash handling architecture built into the sentry-native SDK.
+
+<Alert level="warning">
+
+The native backend is experimental and under active development. It may have incomplete features or unexpected behavior. It is currently not supported in the FAB version of the plugin.
+
+</Alert>
+
+<Alert>
+
+This feature is supported on Windows and Linux only.
+
+</Alert>
+
+## Configuration
+
+The native backend is disabled by default. To enable it, navigate to **Project Settings > Plugins > Sentry > General > Native** and toggle **Use native crash backend (Experimental)**.
+
+Alternatively, add the following to your project's configuration file:
+
+```ini {filename:DefaultEngine.ini}
+[/Script/Sentry.SentrySettings]
+UseNativeBackend=True
+```
+
+Changing this setting requires a rebuild of the project.
+
+### Minidump Mode
+
+Controls how much memory is captured in crash minidumps. You can adjust this in **Project Settings > Plugins > Sentry > General > Native > Minidump capture mode**.
+
+Available modes:
+- `StackOnly` - Capture only stack memory. Fastest and smallest, suitable for production environments with high crash volumes.
+- `Smart` (default) - Capture stack and heap around the crash site. Balanced mode providing good crash analysis without excessive overhead.
+- `Full` - Capture full process memory. Most comprehensive but slowest to generate and upload. Best for development or staging environments.
+
+### Crash Reporting Mode
+
+Controls how crash data is collected and sent to Sentry. You can adjust this in **Project Settings > Plugins > Sentry > General > Native > Crash reporting mode**.
+
+Available modes:
+- `Minidump` - Write and send a minidump for server-side symbolication. No client-side stack unwinding is performed.
+- `NativeStackwalking` - Walk the stack client-side in the crash daemon and send a JSON event with stack traces. No minidump is generated, resulting in faster uploads and smaller payloads.
+- `NativeStackwalkingWithMinidump` (default) - Perform client-side stack unwinding and also attach a minidump for deep debugging when needed.

docs/platforms/unreal/configuration/options.mdx

@@ -153,6 +153,20 @@ On Windows, capturing GPU crashes requires [modifying the Unreal Engine source c
 
 </SdkOption>
 
+<SdkOption name="UseNativeBackend" type="bool" defaultValue="false">
+
+When enabled, the SDK uses the experimental native backend for crash reporting instead of the default Crashpad backend on Windows and Linux. This option requires a rebuild after changing.
+
+See <PlatformLink to="/configuration/native-backend/">Native Backend</PlatformLink> for details and additional configuration options.
+
+<Alert level="warning">
+
+This feature is experimental and under active development. Supported on Windows and Linux only.
+
+</Alert>
+
+</SdkOption>
+
 <SdkOption name="CrashpadWaitForUpload" type="bool" defaultValue="false">
 
 When enabled, application shutdown is delayed until the upload of the crash report is complete. This is useful for deployment in `Docker` environment (Linux and Windows containers) where the life cycle of all processes is bound by the root process (typically the application being monitored).
@@ -161,7 +175,7 @@ This option is turned off by default.
 
 <Alert>
 
-This feature is supported only for Crashpad backend on Windows and Linux (default for the `github` plugin package).
+This feature is supported only for Crashpad backend on Windows and Linux (default for the `github` plugin package). This option has no effect when <PlatformIdentifier name="UseNativeBackend" /> is enabled.
 
 </Alert>