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/PushBranchLevel.kt

@@ -1,5 +1,7 @@
 package solutions.tretter.githugandroid
 
+import java.io.File
+
 /**
  * Port of the upstream ruby-githug `push_branch` level.
  *
@@ -14,6 +16,28 @@ internal fun pushBranchLevel(): Level = level(
     hints = listOf("Investigate the options in `git push` using `git push --help`"),
     commandSuggestions = listOf("git push origin test_branch"),
     setup = { RepoState(initialized = true, branches = mapOf("master" to 2, "other_branch" to 3, "test_branch" to 4), remotes = mapOf("origin" to "remote"), headBranch = "master") },
+    nativeSetup = {
+        resetFiles()
+        write("file1")
+        addCommit("committed changes on master", "file1")
+        val remote = siblingRepo("origin")
+        git("remote", "add", "push-branch-setup-origin", File(remote, ".git").absolutePath)
+        git("push", "push-branch-setup-origin", "master")
+        git("remote", "remove", "push-branch-setup-origin")
+        git(remote, "checkout", "-f", "master")
+        write("file2")
+        addCommit("If this commit gets pushed to repo, then you have lost the level :( ", "file2")
+        checkoutNew("other_branch")
+        write("file3")
+        addCommit("If this commit gets pushed to repo, then you have lost the level :( ", "file3")
+        checkoutNew("test_branch")
+        write("file4")
+        addCommit("committed change on test_branch", "file4")
+        git("remote", "add", "origin", File(remote, ".git").absolutePath)
+        git("branch", "--set-upstream-to=origin/master", "master")
+        checkout("master")
+        true
+    },
     validator = repoPredicate { repo -> "origin/test_branch" in repo.pushedBranches && "origin/master" !in repo.pushedBranches && "origin/other_branch" !in repo.pushedBranches },
     testCases = listOf(
         levelTestCase("push named branch", "git push origin test_branch"),