Add git re-entry alias for packaged runtime helpers

- Add a plain git alias in the runtime git-exec directory so Git's internal `git <helper>` re-entry can resolve on Android.
- Keep prefixed and unprefixed helper aliases plus GIT_EXEC_PATH/PATH wiring for direct helper lookup.
- Verify Push no longer reproduces `cannot run merge-base` or `cannot run fetch` in the host libgit.so runtime tests.

app/build.gradle.kts

@@ -19,8 +19,8 @@ android {
         applicationId = "solutions.tretter.githugandroid"
         minSdk = 26
         targetSdk = 35
-        versionCode = 124
-        versionName = "0.1.123"
+        versionCode = 125
+        versionName = "0.1.124"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
         vectorDrawables.useSupportLibrary = true