[infra] add parameterized runTarget to allow running against custom IDE targets (flutter#8910)

Adds support for running the plugin against custom target IDEs using the
new
[`intellijPlatformTesting`](https://plugins.jetbrains.com/docs/intellij/tools-intellij-platform-gradle-plugin-testing-extension.html)
Gradle extension, introducing a new parameterized `runTarget`.

## Why not update `runIde` directly?

In the new IntelliJ Platform Gradle Plugin (v2.x), the default `runIde`
task is strictly bound to the main project dependency used for
compilation (which is Android Studio in our project). To run against a
different IDE *without* changing the compilation target (which would
break compilation due to our project's hard dependencies on Android
Studio APIs), the plugin requires using the `intellijPlatformTesting`
extension to register a custom task. We can't easily re-target the
default `runIde` task without also changing what we compile against.
(And if we don't change what we compile against we're in the reflection
business so we can compile in the absence of AS deps OR code splitting
which is a headache; see relevant conversation in
flutter#8865.)

## Details
- Registers a custom `runIde` task named `runTarget` in
`build.gradle.kts`.
- Added support for `-Pide` (values: `AndroidStudio`, `IntelliJ`,
`Ultimate`) and `-PideV` (version string or build number) properties.
- Adds a self-documenting help output to `runTarget` that lists
available options and examples when run without parameters, and then
exits without launching the IDE.
- Updates the existing `printProductsReleases` task to include
instructions on how to map its output to the new `-Pide` and `-PideV`
parameters.

---

## Sample Outputs

### 1. Running `runTarget` without parameters
Running the task without parameters prints a help report and stops
execution.

```bash
./gradlew runTarget

============================================================
runTarget - Available Options
============================================================
Valid values for -Pide:
 - AndroidStudio (default)
 - IntelliJ (IntelliJ IDEA Community)
 - Ultimate (IntelliJ IDEA Ultimate)

Valid values for -PideV:
 - Any valid version string for the selected IDE.
 - Examples for IntelliJ/Ultimate: 2024.1, 2024.2, 2024.3, 2025.1
 - Run './gradlew printProductsReleases' to see the full list.

Examples:
 ./gradlew runTarget -Pide=IntelliJ -PideV=2025.1
 ./gradlew runTarget -Pide=Ultimate -PideV=2025.1
============================================================
Stopping execution. Please run with parameters to launch a specific IDE.
```


### 2. Running printProductsReleases
The task now prints mapping instructions after listing the available
releases.

```
./gradlew printProductsReleases

IU-261.23567.71
IU-253.31033.53
IC-252.27397.28

Mapping printProductsReleases output to ideV:
 - The prefix (e.g., IU-, IC-) maps to -Pide (Ultimate, IntelliJ).
 - The number part (e.g., 261.23567.71) maps to -PideV.
 - Example: IU-261.23567.71 -> -Pide=Ultimate -PideV=261.23567.71
```

Fixes: flutter#8909

---

Review the contribution guidelines below:

- [x] I’ve reviewed the contributor guide and applied the relevant
portions to this PR.
- [x] I've included the required information in the description above.
- [x] My up-to-date information is in the `AUTHORS` file.
- [x] I've updated `CHANGELOG.md` if appropriate.

<details>
  <summary>Contribution guidelines:</summary><br>

- See
  our [contributor guide](../CONTRIBUTING.md) and
the [Flutter organization contributor
guide]([https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md)
  for general expectations for PRs.
- Larger or significant changes should be discussed in an issue before
creating a PR.
- Dart contributions to our repos should follow the [Dart style
guide](https://dart.dev/guides/language/effective-dart) and use
  `dart format`.
- Java and Kotlin contributions should strive to follow Java and Kotlin
best
practices
([discussion](flutter#8098)).

</details>

Author: pq

CONTRIBUTING.md

@@ -232,6 +232,23 @@ name and contact info to the [AUTHORS](AUTHORS) file.
     - Expand `Edit configuration templates...` and verify that Flutter is present.
     - Click [+] and verify that Flutter is present.
 
+### Running against custom target IDEs
+
+To test or debug the plugin against a different IDE target (like IntelliJ IDEA Community or Ultimate) without changing the project's compilation target, you can use the custom `runTarget` Gradle task.
+
+Run it from the command line specifying the target IDE and version:
+```bash
+./gradlew runTarget -Pide=IntelliJ -PideV=2025.1
+```
+
+*   **`-Pide`**: Valid values are `AndroidStudio` (default), `IntelliJ` (Community), and `Ultimate`.
+*   **`-PideV`**: Any valid version string or build number for the selected IDE.
+
+To see a full list of available options and usage examples, run the task without any parameters:
+```bash
+./gradlew runTarget
+```
+
 ## Provision Tool
 
 This is not currently required. However, for debugging unit tests, it may be handy; please ignore for now.

build.gradle.kts

@@ -389,12 +389,18 @@ tasks {
 // https://plugins.jetbrains.com/docs/intellij/tools-intellij-platform-gradle-plugin-faq.html#how-to-check-the-latest-available-eap-release
 tasks {
   printProductsReleases {
-    channels = listOf(ProductRelease.Channel.EAP)
-    types = listOf(IntelliJPlatformType.IntellijIdeaCommunity)
+    channels = listOf(ProductRelease.Channel.RELEASE, ProductRelease.Channel.EAP)
+    types = listOf(IntelliJPlatformType.IntellijIdeaCommunity, IntelliJPlatformType.IntellijIdeaUltimate)
     untilBuild = provider { null }
 
     doLast {
       productsReleases.get().max()
+      println()
+      println("Mapping printProductsReleases output to ideV:")
+      println(" - The prefix (e.g., IU-, IC-) maps to -Pide (Ultimate, IntelliJ).")
+      println(" - The number part (e.g., 261.23567.71) maps to -PideV.")
+      println(" - Example: IU-261.23567.71 -> -Pide=Ultimate -PideV=261.23567.71")
+      println()
     }
   }
   prepareJarSearchableOptions {
@@ -415,6 +421,53 @@ tasks {
   }
 }
 
+intellijPlatformTesting {
+  runIde {
+    register("runTarget") {
+      val target = project.findProperty("ide") as? String
+      val version = project.findProperty("ideV") as? String
+      
+      val actualTarget = target ?: "AndroidStudio"
+      type = when (actualTarget) {
+        "IntelliJ" -> IntelliJPlatformType.IntellijIdeaCommunity
+        "Ultimate" -> IntelliJPlatformType.IntellijIdeaUltimate
+        else -> IntelliJPlatformType.AndroidStudio
+      }
+      this.version = version ?: ideaVersion
+    }
+  }
+}
+
+tasks.named("runTarget") {
+  val target = project.findProperty("ide") as? String
+  val version = project.findProperty("ideV") as? String
+  
+  doFirst {
+    if (target == null && version == null) {
+      println("============================================================")
+      println("runTarget - Available Options")
+      println("============================================================")
+      println("Valid values for -Pide:")
+      println(" - AndroidStudio (default)")
+      println(" - IntelliJ (IntelliJ IDEA Community)")
+      println(" - Ultimate (IntelliJ IDEA Ultimate)")
+      println()
+      println("Valid values for -PideV:")
+      println(" - Any valid version string for the selected IDE.")
+      println(" - Examples for IntelliJ/Ultimate: 2024.1, 2024.2, 2024.3, 2025.1")
+      println(" - Run './gradlew printProductsReleases' to see the full list.")
+      println()
+      println("Examples:")
+      println(" ./gradlew runTarget -Pide=IntelliJ -PideV=2025.1")
+      println(" ./gradlew runTarget -Pide=Ultimate -PideV=2025.1")
+      println("============================================================")
+      println("Stopping execution. Please run with parameters to launch a specific IDE.")
+      
+      throw org.gradle.api.tasks.StopExecutionException()
+    }
+  }
+}
+
 // A task to print the classpath used for compiling an IntelliJ plugin
 // Run with `./gradlew printCompileClasspath --no-configuration-cache `
 tasks.register<Task>("printCompileClasspath") {