fix: make miro testdir resolution explicit based on config

internal/miro/init.go

@@ -1,6 +1,38 @@
 package miro
 
-// Init is the current no-op initializer placeholder.
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	miroconfig "miro/internal/config"
+)
+
+const defaultTestDir = "e2e"
+
+// Init creates the default config when missing and leaves valid config untouched.
 func Init() error {
+	root, err := currentProjectRoot()
+	if err != nil {
+		return err
+	}
+
+	configPath := filepath.Join(root, "miro.toml")
+	if _, err := os.Stat(configPath); err == nil {
+		if _, err := miroconfig.ReadConfig(configPath); err != nil {
+			return err
+		}
+		return nil
+	} else if !errors.Is(err, os.ErrNotExist) {
+		return fmt.Errorf("failed to check %s: %v", configPath, err)
+	}
+
+	if err := miroconfig.WriteConfig(configPath, miroconfig.Config{
+		TestDir: defaultTestDir,
+	}); err != nil {
+		return fmt.Errorf("failed to write %s: %v", configPath, err)
+	}
+
 	return nil
 }