Add app-native interactive Git dialogs

- Open an interactive staging dialog for `git add -i`, `git stage -i`, and
  `git add --interactive`, allowing paths to be selected before staging.
- Open an interactive rebase dialog for `git rebase -i` / `--interactive`, with
  pick, squash, drop, commit-message editing, and reorder controls.
- Keep the existing synthetic runtime behavior available for direct engine/test calls,
  while making app-entered interactive commands show real UI instead of auto-staging.
- Center manpage search navigation using actual text-layout highlight bounds instead
  of approximate line and column math.
- Make editor dialogs use a full-screen IME-padded outer scroll container so controls
  remain reachable when the keyboard pans or resizes the dialog.

app/build.gradle.kts

@@ -19,8 +19,8 @@ android {
         applicationId = "solutions.tretter.githugandroid"
         minSdk = 26
         targetSdk = 35
-        versionCode = 131
-        versionName = "0.1.130"
+        versionCode = 132
+        versionName = "0.1.131"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
         vectorDrawables.useSupportLibrary = true