Move native level setups into level files

- Delete NativeLevelFixtures.kt and make native repository setup an optional property of each Level.
- Move every existing native setup into its corresponding level file so setup, validation, and tests stay together.
- Add the missing Blame native setup with config.rb history and a Spider Man password commit.
- Add a native runtime regression that verifies `git blame config.rb` identifies Spider Man on the password line.
- Verify the full JVM test suite using the compiled host Git runtime.

app/src/main/java/solutions/tretter/githugandroid/levels/PullLevel.kt

@@ -1,5 +1,7 @@
 package solutions.tretter.githugandroid
 
+import java.io.File
+
 /**
  * Port of the upstream ruby-githug `pull` level.
  *
@@ -14,6 +16,22 @@ internal fun pullLevel(): Level = level(
     hints = listOf("Check out the remote repositories and research `git pull`."),
     commandSuggestions = listOf("git pull origin master"),
     setup = { RepoState(initialized = true, remotes = mapOf("origin" to "remote"), branches = mapOf("master" to 1)) },
+    nativeSetup = {
+        resetFiles()
+        write("local_file")
+        addCommit("Initial local commit", "local_file")
+        val remote = siblingRepo("origin")
+        git("remote", "add", "pull-setup-origin", File(remote, ".git").absolutePath)
+        git("push", "pull-setup-origin", "master")
+        git("remote", "remove", "pull-setup-origin")
+        git(remote, "checkout", "-f", "master")
+        writeIn(remote, "remote_file", "pulled from origin\n")
+        addCommitIn(remote, "Pulled commit", "remote_file")
+        git("remote", "add", "origin", File(remote, ".git").absolutePath)
+        git("config", "branch.master.remote", "origin")
+        git("config", "branch.master.merge", "refs/heads/master")
+        true
+    },
     validator = repoPredicate { repo ->
         "origin/master" in repo.fetchedBranches &&
             repo.files.any { it.name == "remote_file" && it.tracked } &&