docs(rum): say that Flutter iOS Dart stacks are not symbolicated

The symbolication tables listed a single `Dart` row pointing at Flutter symbols, with no
platform qualifier, so they read as a promise that iOS Dart frames resolve the same way
Android ones do. They do not: the `.symbols` file Flutter produces for iOS carries no
build id (flutter/flutter#138182, open since 2023), so it cannot be matched to a build
and the upload rejects it.

The omission cost more than a failed upload. Readers following these pages ran
`--obfuscate` on their iOS builds, and with no uploadable symbol file nothing can ever
un-rename those symbols -- so the Dart stacks they were trying to make readable became
permanently unreadable instead.

Split the Dart row by platform and add the reason, the `--obfuscate` warning, and the
note that iOS native crashes are unaffected and still symbolicate from dSYMs.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: Fiona2016

en/rum/sdk/flutter/advanced-config.mdx

@@ -88,10 +88,15 @@ To resolve crash and error stacks back to source locations, you need to upload s
 
 | Frame type | Required files | How to generate |
 |----------|----------|----------|
-| Dart | Flutter symbols | `flutter build --split-debug-info=<dir> --obfuscate` |
+| Dart (Android) | Flutter symbols | `flutter build apk --split-debug-info=<dir> --obfuscate` |
+| Dart (iOS) | Not supported yet, see the note below | — |
 | iOS Native | dSYM | Xcode build output |
 | Android Native | mapping files | R8 / ProGuard output |
 
+<Warning>
+**Dart stacks cannot be symbolicated on iOS yet.** The `.symbols` file Flutter produces for iOS carries no build id ([flutter/flutter#138182](https://github.com/flutter/flutter/issues/138182)), so it cannot be matched to a build and cannot be uploaded. Do not enable `--obfuscate` for iOS builds, or your Dart stacks will be unrecoverable. iOS native crashes are unaffected — upload dSYMs to symbolicate them.
+</Warning>
+
 Use the FlashCat CLI to upload symbol files:
 
 ```bash

en/rum/sdk/flutter/compatible.mdx

@@ -60,10 +60,15 @@ Flutter crash stacks can contain both Dart frames and native (iOS / Android) fra
 
 | Frame type | Required uploaded files |
 |----------|--------------|
-| Dart | Flutter symbols (`flutter build --split-debug-info` output) |
+| Dart (Android) | Flutter symbols (`flutter build --split-debug-info` output) |
+| Dart (iOS) | Not supported yet, see the note below |
 | iOS Native | dSYM |
 | Android Native | mapping files |
 
+<Warning>
+**Dart stacks cannot be symbolicated on iOS yet.** The `.symbols` file Flutter produces for iOS carries no build id ([flutter/flutter#138182](https://github.com/flutter/flutter/issues/138182)), so it cannot be matched to a build and cannot be uploaded. Do not enable `--obfuscate` for iOS builds, or your Dart stacks will be unrecoverable. iOS native crashes are unaffected — upload dSYMs to symbolicate them.
+</Warning>
+
 <Tip>
 Symbol files are uploaded through the FlashCat CLI, and the `version` used at upload time must match the `version` in the SDK initialization. Otherwise the console can receive crash events but cannot resolve the stacks.
 </Tip>

zh/rum/sdk/flutter/advanced-config.mdx

@@ -88,10 +88,15 @@ DatadogRumConfiguration(
 
 | 栈帧类型 | 所需文件 | 生成方式 |
 |----------|----------|----------|
-| Dart | Flutter symbols | `flutter build --split-debug-info=<dir> --obfuscate` |
+| Dart（Android） | Flutter symbols | `flutter build apk --split-debug-info=<dir> --obfuscate` |
+| Dart（iOS） | 暂不支持，见下方说明 | — |
 | iOS Native | dSYM | Xcode 构建产物 |
 | Android Native | mapping 文件 | R8 / ProGuard 产物 |
 
+<Warning>
+**iOS 的 Dart 堆栈暂不支持符号化。** Flutter 为 iOS 生成的 `.symbols` 不包含 build id（[flutter/flutter#138182](https://github.com/flutter/flutter/issues/138182)），无法与具体构建对应，因此无法上传使用。iOS 构建请勿开启 `--obfuscate`，否则 Dart 堆栈将无法还原。iOS 原生崩溃不受影响，上传 dSYM 即可符号化。
+</Warning>
+
 使用 FlashCat CLI 上传符号文件：
 
 ```bash

zh/rum/sdk/flutter/compatible.mdx

@@ -60,10 +60,15 @@ Flutter 崩溃栈可能同时包含 Dart 帧与原生（iOS / Android）帧。
 
 | 栈帧类型 | 所需上传文件 |
 |----------|--------------|
-| Dart | Flutter symbols（`flutter build --split-debug-info` 产物） |
+| Dart（Android） | Flutter symbols（`flutter build --split-debug-info` 产物） |
+| Dart（iOS） | 暂不支持，见下方说明 |
 | iOS Native | dSYM |
 | Android Native | mapping 文件 |
 
+<Warning>
+**iOS 的 Dart 堆栈暂不支持符号化。** Flutter 为 iOS 生成的 `.symbols` 不包含 build id（[flutter/flutter#138182](https://github.com/flutter/flutter/issues/138182)），无法与具体构建对应，因此无法上传使用。iOS 构建请勿开启 `--obfuscate`，否则 Dart 堆栈将无法还原。iOS 原生崩溃不受影响，上传 dSYM 即可符号化。
+</Warning>
+
 <Tip>
 符号文件通过 FlashCat CLI 上传，且上传时的 `version` 必须与 SDK 初始化中的 `version` 一致，否则控制台可以收到崩溃事件，但无法还原堆栈。
 </Tip>