[skills] Strengthen Java name conversion reviews

.github/skills/android-reviewer/SKILL.md

@@ -62,7 +62,7 @@ Review the CI results. **Never post ✅ LGTM if any required CI check is failing
 
 ### 5. Load review rules
 
-Based on the file types identified in step 2, read the appropriate rule files from this skill's `references/` directory.
+Based on the changed files and diff content identified in step 2, read the appropriate rule files from this skill's `references/` directory.
 
 **Always load:**
 - `references/repo-conventions.md` — Formatting, style, and patterns specific to this repository.
@@ -72,7 +72,7 @@ Based on the file types identified in step 2, read the appropriate rule files fr
 - `references/csharp-rules.md` — When any `.cs` files changed. Covers nullable, async, error handling, performance, and code organization.
 - `references/msbuild-rules.md` — When `.targets`, `.props`, `.projitems`, or `.csproj` files changed, or when MSBuild task C# files changed (e.g., files under `src/Xamarin.Android.Build.Tasks/` or `external/xamarin-android-tools/src/Microsoft.Android.Build.BaseTasks/`).
 - `references/native-rules.md` — When `.c`, `.cpp`, `.h`, or `.hpp` files changed. Covers memory management, C++ best practices, symbol visibility, and platform-specific code.
-- `references/interop-rules.md` — When both C# and native files changed, when the diff contains P/Invoke or JNI interop code (e.g., `DllImport`, `[Register]` attribute changes, `JNIEnv` calls, `[MarshalAs]`, `[StructLayout]`, `JniObjectReference`, `JniPeerMembers`, `JniTransition`), or when files under `external/Java.Interop/`, `src/Mono.Android/`, or `src/native/` changed.
+- `references/interop-rules.md` — When interop markers or Java/JNI name conversions appear, or files under `external/Java.Interop/`, `src/Mono.Android/`, `src/native/`, or `src/Microsoft.Android.Sdk.TrimmableTypeMap/` change.
 - `references/testing-rules.md` — When test files changed (e.g., files under `tests/`, `**/Tests/`, or test project directories).
 - `references/security-rules.md` — When any code files changed (C#, C/C++, or MSBuild).
 

.github/skills/android-reviewer/references/interop-rules.md

@@ -1,9 +1,8 @@
 # Managed ↔ Native Interop Review Rules
 
-Rules for the boundary between C# and C/C++ code — P/Invoke declarations, JNI
-bindings, and shared structs. Load when both managed and native files change, or
-when the diff contains interop markers (`JniObjectReference`, `JniPeerMembers`,
-`DllImport`, `[Register]`, `JNIEnv`, `[MarshalAs]`, `[StructLayout]`).
+Rules for managed/native boundaries and Java/JNI name handling. Load for interop
+markers, Java/JNI name conversions, or changes under Java.Interop, Mono.Android,
+native runtime, or TrimmableTypeMap paths.
 
 ---
 
@@ -21,6 +20,23 @@ when the diff contains interop markers (`JniObjectReference`, `JniPeerMembers`,
 
 ---
 
+## Java Type Names
+
+Determine the required representation at each changed call site:
+
+| Representation | Nested-class example | Typical consumers |
+|----------------|----------------------|-------------------|
+| **JNI internal name** | `android/view/View$OnClickListener` | JNI registration, descriptors after removing `L`/`;`, runtime JNI lookup |
+| **Java binary name** | `android.view.View$OnClickListener` | `Class.forName`, Android manifests, ACW maps, ProGuard/R8 class rules |
+| **Java source name** | `android.view.View.OnClickListener` | Generated `.java` type references such as `extends`, `implements`, parameters, and return types |
+| **Managed nested type name** | `Android.Views.View+IOnClickListener` | Managed metadata and assembly-qualified names |
+
+- Read conversion helpers instead of trusting their names, and compare their full behavior with any inline logic they replace.
+- Trace serialized names to the final consumer; correctness is per call site.
+- Preserve `$` for binary-name consumers. Replace it with `.` only for Java source names.
+
+---
+
 ## P/Invoke & Marshaling Checks
 
 | Check | What to look for |

.github/skills/android-reviewer/references/testing-rules.md

@@ -20,3 +20,4 @@ Guidance for test code. The repo-specific conventions (e.g., `BaseTest`,
 | **Generator tests must include Invoker types** | Tests for generated binding code (under `external/Java.Interop/tools/generator/` and related test projects) should verify both the interface/class output and the `*Invoker` type behavior. Invoker codegen has historically had subtle bugs with default interface methods and virtual dispatch. |
 | **JVM-dependent tests** | Tests that require a running JVM must be in projects that configure the JVM environment (e.g., `Java.Interop-Tests`). Verify that test classes requiring a JVM are not placed in unit-test-only projects, where they will silently skip or fail with obscure errors. |
 | **Expected codegen output tests** | Generator tests that compare against expected output files should be updated when the expected format changes. Stale expected-output files cause spurious test failures that mask real regressions. |
+| **Test nested Java/JNI names at boundaries** | Name-conversion tests must include a `$` nested type and assert the final manifest, map, rule, or generated-source output—not only the helper. |