docs: iOS parity, fetch control, and deprecation notice updates

Because

* iOS integration guide was missing recordMalformedConfiguration()
  that was added to the Android guide
* setFetchEnabled/isFetchEnabled QA methods were undocumented
* Deprecated custom-targeting docs didn't link to the new
  recordedContext builder option in the integration guides

This commit

* Adds recordMalformedConfiguration() section to iOS integration guide
* Adds setFetchEnabled/isFetchEnabled section to mobile-ui.md
* Updates deprecated custom-targeting notices on both Android and iOS
  to link to the integration guide's recordedContext section

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jaredlockhart

docs/platform-guides/android/custom-targeting.md

@@ -5,7 +5,7 @@ slug: /platform-guides/android/custom-targeting
 ---
 
 :::warning DEPRECATED
-**This method of adding new targeting attributes is deprecated. Please use the method described in the [Recorded Targeting Context doc](/advanced/recording-targeting-context#adding-new-fields).**
+**This method of adding new targeting attributes is deprecated.** Use the `recordedContext` NimbusBuilder option instead — see the [integration guide](/platform-guides/android/integration#connecting-to-the-recorded-targeting-context) and the [Recorded Targeting Context doc](/advanced/recording-targeting-context#adding-new-fields) for details.
 :::
 
 ## Adding New Targeting Attributes to Android

docs/platform-guides/android/mobile-ui.md

@@ -40,6 +40,15 @@ This disqualifies existing enrollments. and breaks any connection with experimen
 
 [nimbus-cli]: https://github.com/mozilla/application-services/tree/main/components/support/nimbus-cli
 
+### Disabling Experiment Fetch
+
+For QA testing, you can disable fetching of experiments from Remote Settings. This is used by the `nimbus-cli` tooling and is not intended for end users.
+
+```kotlin
+nimbus.setFetchEnabled(false) // disable fetching
+nimbus.isFetchEnabled()       // check current state
+```
+
 ### Preview Collection
 
 To allow testing of experiments before they are published, the client should allow configuring the Nimbus startup to use the `preview-collection`.

docs/platform-guides/ios/custom-targeting.md

@@ -6,7 +6,7 @@ slug: /platform-guides/ios/custom-targeting
 ## Adding New Targeting Attributes to iOS
 
 :::warning DEPRECATED
-**This method of adding new targeting attributes is deprecated. Please use the method described in the [Recorded Targeting Context doc](/advanced/recording-targeting-context#adding-new-fields).**
+**This method of adding new targeting attributes is deprecated.** Use the `recordedContext` NimbusBuilder option instead — see the [integration guide](/platform-guides/ios/integration#connecting-to-the-recorded-targeting-context) and the [Recorded Targeting Context doc](/advanced/recording-targeting-context#adding-new-fields) for details.
 :::
 
 This page demonstrates how to add new targeting attributes to iOS, enabling experiment creators more specific targeting.

docs/platform-guides/ios/integration.md

@@ -184,6 +184,16 @@ To connect the `NimbusInterface` object to the command line, we need to feed the
         .build(appInfo: appInfo)
 ```
 
+### Reporting malformed feature configuration
+
+If your app detects that a feature configuration from an experiment is invalid or malformed, you can report it as telemetry using `recordMalformedConfiguration`:
+
+```swift
+AppConfig.shared.features.newtab.recordMalformedConfiguration(partId: "invalid-card")
+```
+
+This sends a `malformedConfiguration` Glean event identifying the feature and the specific part that was invalid.
+
 ## A complete `NimbusBuilder` example
 
 ```swift