✨ feat(storage): 支持自定义数据目录与显式迁移

Fixes #242

internal/appdata/root_test.go

@@ -0,0 +1,69 @@
+package appdata
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestResolveActiveRootDefaultsToLegacyGonaviDir(t *testing.T) {
+	homeDir := t.TempDir()
+	t.Setenv("HOME", homeDir)
+	t.Setenv("USERPROFILE", homeDir)
+
+	root, err := ResolveActiveRoot()
+	if err != nil {
+		t.Fatalf("ResolveActiveRoot returned error: %v", err)
+	}
+	expected := filepath.Join(homeDir, ".gonavi")
+	if root != expected {
+		t.Fatalf("expected default root %q, got %q", expected, root)
+	}
+}
+
+func TestSetActiveRootWritesBootstrapAndResolveUsesIt(t *testing.T) {
+	homeDir := t.TempDir()
+	t.Setenv("HOME", homeDir)
+	t.Setenv("USERPROFILE", homeDir)
+
+	customRoot := filepath.Join(t.TempDir(), "gonavi-data")
+	savedRoot, err := SetActiveRoot(customRoot)
+	if err != nil {
+		t.Fatalf("SetActiveRoot returned error: %v", err)
+	}
+	if savedRoot != customRoot {
+		t.Fatalf("expected saved root %q, got %q", customRoot, savedRoot)
+	}
+	if _, err := os.Stat(BootstrapPath()); err != nil {
+		t.Fatalf("expected bootstrap file to exist: %v", err)
+	}
+	resolvedRoot, err := ResolveActiveRoot()
+	if err != nil {
+		t.Fatalf("ResolveActiveRoot returned error: %v", err)
+	}
+	if resolvedRoot != customRoot {
+		t.Fatalf("expected custom root %q, got %q", customRoot, resolvedRoot)
+	}
+}
+
+func TestSetActiveRootResetToDefaultRemovesBootstrap(t *testing.T) {
+	homeDir := t.TempDir()
+	t.Setenv("HOME", homeDir)
+	t.Setenv("USERPROFILE", homeDir)
+
+	customRoot := filepath.Join(t.TempDir(), "gonavi-data")
+	if _, err := SetActiveRoot(customRoot); err != nil {
+		t.Fatalf("SetActiveRoot custom returned error: %v", err)
+	}
+	defaultRoot, err := SetActiveRoot("")
+	if err != nil {
+		t.Fatalf("SetActiveRoot default returned error: %v", err)
+	}
+	expectedDefault := filepath.Join(homeDir, ".gonavi")
+	if defaultRoot != expectedDefault {
+		t.Fatalf("expected default root %q, got %q", expectedDefault, defaultRoot)
+	}
+	if _, err := os.Stat(BootstrapPath()); !os.IsNotExist(err) {
+		t.Fatalf("expected bootstrap file to be removed, got err=%v", err)
+	}
+}