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/src/main/java/solutions/tretter/githugandroid/GitRuntime.kt

@@ -853,6 +853,7 @@ class GitRepositoryRuntime private constructor(
                 .apply {
                     environment()["HOME"] = workingDir.absolutePath
                     environment()["GIT_EXEC_PATH"] = gitExecPath.absolutePath
+                    environment()["PATH"] = gitExecPath.absolutePath
                     environment()["GIT_CONFIG_NOSYSTEM"] = "1"
                     environment()["GIT_AUTHOR_NAME"] = "GitHug"
                     environment()["GIT_AUTHOR_EMAIL"] = "githug@example.com"
@@ -878,12 +879,19 @@ class GitRepositoryRuntime private constructor(
         }
         directory.mkdirs()
 
-        RequiredGitCommandAliases.forEach { command ->
-            val alias = File(directory, "git-$command")
+        File(directory, "git").also { alias ->
             if (!alias.exists()) {
                 createGitAlias(binary, alias)
             }
         }
+        RequiredGitCommandAliases.forEach { command ->
+            listOf("git-$command", command).forEach { aliasName ->
+                val alias = File(directory, aliasName)
+                if (!alias.exists()) {
+                    createGitAlias(binary, alias)
+                }
+            }
+        }
         return directory
     }