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/GameModels.kt

@@ -1,6 +1,7 @@
 package solutions.tretter.githugandroid
 
 import androidx.compose.runtime.saveable.listSaver
+import java.io.File
 
 enum class PlayMode(val label: String) {
     CLI_ONLY("CLI ONLY"),
@@ -46,6 +47,7 @@ data class Level(
     val commandSuggestions: List<String>,
     val validator: (RepoState, String) -> Boolean,
     val setup: () -> RepoState,
+    val nativeSetup: (NativeLevelSetup.() -> Boolean)? = null,
     val testCases: List<LevelTestCase> = emptyList(),
 )
 
@@ -54,6 +56,91 @@ data class LevelTestCase(
     val commands: List<String>,
 )
 
+class NativeLevelSetup internal constructor(
+    internal val sandbox: File,
+    private val runGit: (File, List<String>) -> Int,
+) {
+    fun resetFiles() {
+        sandbox.listFiles()
+            ?.filterNot { it.name == ".git" }
+            ?.forEach { it.deleteRecursively() }
+        git("checkout", "-B", "master")
+    }
+
+    fun git(vararg arguments: String): Int = runGit(sandbox, arguments.toList())
+
+    fun git(directory: File, vararg arguments: String): Int = runGit(directory, arguments.toList())
+
+    fun initRepo(directory: File) {
+        directory.mkdirs()
+        val initResult = git(directory, "init", "-b", "master")
+        if (initResult != 0) {
+            git(directory, "init")
+            git(directory, "checkout", "-B", "master")
+        }
+        git(directory, "config", "receive.denyCurrentBranch", "ignore")
+    }
+
+    fun write(path: String, content: String = "") {
+        File(sandbox, path).apply {
+            parentFile?.mkdirs()
+            writeText(content)
+        }
+    }
+
+    fun append(path: String, content: String) {
+        File(sandbox, path).appendText(content)
+    }
+
+    fun add(vararg paths: String) {
+        git("add", *paths)
+    }
+
+    fun commit(message: String, author: String? = null) {
+        if (author == null) {
+            git("commit", "-m", message)
+        } else {
+            git("commit", "--author", author, "-m", message)
+        }
+    }
+
+    fun addCommit(message: String, vararg paths: String, author: String? = null) {
+        add(*paths)
+        commit(message, author)
+    }
+
+    fun writeIn(directory: File, path: String, content: String = "") {
+        File(directory, path).apply {
+            parentFile?.mkdirs()
+            writeText(content)
+        }
+    }
+
+    fun addCommitIn(directory: File, message: String, vararg paths: String) {
+        git(directory, "add", *paths)
+        git(directory, "commit", "-m", message)
+    }
+
+    fun siblingRepo(name: String): File {
+        val directory = File(sandbox.parentFile ?: sandbox, "${sandbox.name}-$name")
+        directory.deleteRecursively()
+        initRepo(directory)
+        return directory
+    }
+
+    fun checkoutNew(branch: String) {
+        git("checkout", "-b", branch)
+    }
+
+    fun checkout(branch: String) {
+        git("checkout", branch)
+    }
+
+    fun tag(name: String) {
+        git("tag", "-f", name)
+    }
+}
+
 fun sampleLevels(): List<Level> = allGithugLevels()
 
 val RepoStateSaver = listSaver<RepoState, Any>(