chore: restructure dotnet build targets for local development

.github/workflows/sdk.yml

@@ -26,7 +26,8 @@ jobs:
         shell: bash
         run: |
           if [[ "${TARGET}" == "Android" ]]; then
-            submodules="modules/sentry-java"
+            # Android needs sentry-native too — BuildAndroidSDK builds the NDK from source.
+            submodules="modules/sentry-java modules/sentry-native"
           elif [[ "${TARGET}" == "Cocoa" ]]; then
             submodules="modules/sentry-cocoa"
           else
@@ -62,7 +63,7 @@ jobs:
           # hash of package/package.json for cache busting on release builds (version bump)
           path: |
             package-dev/Plugins
-          key: sdk=${{ env.TARGET }}-${{ hashFiles('submodules-status', 'package/package.json', 'Directory.Build.targets', 'sdk-static/**', 'scripts/build-cocoa-sdk.ps1') }}
+          key: sdk=${{ env.TARGET }}-${{ hashFiles('submodules-status', 'package/package.json', 'Directory.Build.targets', 'build/native-sdks.targets', 'sdk-static/**', 'scripts/build-cocoa-sdk.ps1', 'scripts/build-native-ndk-local.ps1') }}
 
       - name: Installing Linux Dependencies
         if: ${{ env.TARGET == 'Linux' && steps.cache.outputs.cache-hit != 'true' }}

CLAUDE.md

@@ -148,17 +148,19 @@ Builds run in Docker containers using `ghcr.io/unityci/editor` images:
 
 ### MSBuild Targets
 
-Key targets defined in `Directory.Build.targets`:
-
-| Target               | Purpose                                 |
-| -------------------- | --------------------------------------- |
-| `DownloadNativeSDKs` | Downloads prebuilt native SDKs from CI  |
-| `BuildAndroidSDK`    | Builds Android SDK via Gradle           |
-| `BuildLinuxSDK`      | Builds Linux SDK via CMake              |
-| `BuildWindowsSDK`    | Builds Windows SDK via CMake (Crashpad) |
-| `BuildCocoaSDK`      | Downloads iOS/macOS SDKs from releases  |
-| `UnityEditModeTest`  | Runs edit-mode unit tests               |
-| `UnityPlayModeTest`  | Runs play-mode tests                    |
+Key targets defined across `build/` target files:
+
+| Target                  | Purpose                                                                 |
+| ----------------------- | ----------------------------------------------------------------------- |
+| `BuildCocoaSDK`         | Builds iOS + macOS SDKs via Xcode (`build/native-sdks.targets`)          |
+| `BuildAndroidSDK`       | Builds Android SDK via Gradle (`build/native-sdks.targets`)              |
+| `BuildLinuxSDK`         | Builds Linux SDK via CMake (`build/native-sdks.targets`)                 |
+| `BuildWindowsSDK`       | Builds Windows SDK via CMake + Crashpad (`build/native-sdks.targets`)    |
+| `Ensure<Platform>SDK`   | Auto-bootstrap wrapper; fires from `dotnet build` when artifacts missing |
+| `PublishNativeNdkLocal` | Builds and publishes `sentry-native-ndk` to `~/.m2`                      |
+| `DownloadNativeSDKs`    | Downloads prebuilt native SDKs from CI (`build/local-dev.targets`)       |
+| `UnityEditModeTest`     | Runs edit-mode unit tests                                                |
+| `UnityPlayModeTest`     | Runs play-mode tests                                                     |
 
 ### Artifact Caching
 
@@ -190,7 +192,7 @@ Key targets defined in `Directory.Build.targets`:
 
 ### Build System
 
-Central configuration in `Directory.Build.targets` (900+ lines) and `Directory.Build.props`:
+Core build configuration in `Directory.Build.props`. Build targets are split across `Directory.Build.targets` (CI-shared: `FindUnity`, Unity test/configure targets), `build/native-sdks.targets` (native SDK builders), and `build/local-dev.targets` (developer convenience targets):
 
 ```xml
 <!-- Key properties -->
@@ -320,6 +322,41 @@ modules/
 └── sentry-cocoa/   # iOS/macOS (prebuilt XCFramework)
 ```
 
+### Local Android NDK Development
+
+`BuildAndroidSDK` builds the NDK from source on every run (via `PublishNativeNdkLocal`)
+and ships the resulting AAR alongside the sentry-java artifacts. Both
+`modules/sentry-java` AND `modules/sentry-native` must be checked out — the target
+aborts otherwise and prints the `git submodule update --init` command.
+
+sentry-java's `dependencyResolutionManagement` block already lists `mavenLocal()`,
+so Gradle resolves whatever version is declared in
+`modules/sentry-java/gradle/libs.versions.toml` — falling through to Maven Central
+when the version isn't found locally.
+
+**The local build must publish a version that is NOT available on Maven Central.**
+Otherwise Gradle uses the released artifact on Central (listed before `mavenLocal()`
+in the repositories block) and your local changes are silently ignored.
+
+To iterate on NDK code:
+
+1. Bump the version in the sentry-native NDK source to something unique — e.g.
+   add a `-dev`, `-SNAPSHOT`, or hash suffix that doesn't exist on Maven Central.
+2. Bump the matching `sentry-native-ndk` version in
+   `modules/sentry-java/gradle/libs.versions.toml` to the same value.
+3. Run `dotnet msbuild /t:BuildAndroidSDK src/Sentry.Unity`. The target rebuilds
+   the NDK, publishes it to `~/.m2`, then builds sentry-java against the local
+   artifact.
+
+To refresh only `~/.m2` without rebuilding the Android SDK:
+
+```bash
+dotnet msbuild /t:PublishNativeNdkLocal src/Sentry.Unity
+# Purge cached Gradle artifacts (use when iterating on NDK source without
+# bumping the version, so Gradle re-resolves rather than reusing its cache):
+dotnet msbuild /t:PublishNativeNdkLocal src/Sentry.Unity -p:PurgeNdkCache=true
+```
+
 ### Key Source Files
 
 **Android (`src/Sentry.Unity.Android/`):**