Fix help callout anchoring and Push remote setup

- Anchor startup help callouts inside the scrollable pane workspace so they scroll with the exercise and terminal content they point at.
- Rebuild the Push level remote as a bare sibling repo with a temporary worktree for the remote-only commit, avoiding Android non-bare remote push failures.
- Leave a visible local worktree edit in Push while enabling rebase autostash so status, diff, and pull --rebase all behave as expected.
- Add native Push setup coverage for diverged status output, plain diff output, and clean pull --rebase behavior.

app/build.gradle.kts

@@ -19,8 +19,8 @@ android {
         applicationId = "solutions.tretter.githugandroid"
         minSdk = 26
         targetSdk = 35
-        versionCode = 121
-        versionName = "0.1.120"
+        versionCode = 122
+        versionName = "0.1.121"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
         vectorDrawables.useSupportLibrary = true