fix: correct macOS pref domain splitting and consolidate pref types

- Use LastIndex instead of Index when splitting domain.key input, so
  compound domains like com.apple.dock.tilesize correctly produce
  domain=com.apple.dock, key=tilesize
- Remove omitempty from snapshot.MacOSPref.Type to prevent silent type
  loss during JSON round-trips; empty type continues to trigger
  InferPreferenceType at execution time
- Remove redundant SnapshotMacOSPref struct; Config.SnapshotMacOS now
  uses RemoteMacOSPref directly, eliminating two field-by-field copy loops

Author: fullstackjam

internal/cli/snapshot.go

@@ -717,9 +717,9 @@ func buildImportConfig(edited *snapshot.Snapshot, dryRun bool) *config.Config {
 		cfg.DotfilesURL = edited.Dotfiles.RepoURL
 	}
 
-	cfg.SnapshotMacOS = make([]config.SnapshotMacOSPref, len(edited.MacOSPrefs))
+	cfg.SnapshotMacOS = make([]config.RemoteMacOSPref, len(edited.MacOSPrefs))
 	for i, p := range edited.MacOSPrefs {
-		cfg.SnapshotMacOS[i] = config.SnapshotMacOSPref{
+		cfg.SnapshotMacOS[i] = config.RemoteMacOSPref{
 			Domain: p.Domain,
 			Key:    p.Key,
 			Type:   p.Type,

internal/config/config.go

@@ -50,7 +50,7 @@ type Config struct {
 
 	SnapshotShell    *SnapshotShellConfig
 	SnapshotGit      *SnapshotGitConfig
-	SnapshotMacOS    []SnapshotMacOSPref
+	SnapshotMacOS    []RemoteMacOSPref
 	SnapshotDotfiles string
 	DotfilesURL      string
 	PostInstall      string
@@ -68,14 +68,6 @@ type SnapshotGitConfig struct {
 	UserEmail string
 }
 
-type SnapshotMacOSPref struct {
-	Domain string
-	Key    string
-	Type   string
-	Value  string
-	Desc   string
-}
-
 type RemoteConfig struct {
 	Username     string   `json:"username"`
 	Slug         string   `json:"slug"`

internal/installer/installer.go

@@ -167,16 +167,7 @@ func runCustomInstall(cfg *config.Config) error {
 	}
 
 	if len(cfg.RemoteConfig.MacOSPrefs) > 0 {
-		cfg.SnapshotMacOS = make([]config.SnapshotMacOSPref, len(cfg.RemoteConfig.MacOSPrefs))
-		for i, p := range cfg.RemoteConfig.MacOSPrefs {
-			cfg.SnapshotMacOS[i] = config.SnapshotMacOSPref{
-				Domain: p.Domain,
-				Key:    p.Key,
-				Type:   p.Type,
-				Value:  p.Value,
-				Desc:   p.Desc,
-			}
-		}
+		cfg.SnapshotMacOS = cfg.RemoteConfig.MacOSPrefs
 		if err := stepRestoreMacOS(cfg); err != nil {
 			ui.Error(fmt.Sprintf("macOS configuration failed: %v", err))
 			softErrs = append(softErrs, fmt.Errorf("macos: %w", err))

internal/snapshot/snapshot.go

@@ -36,7 +36,7 @@ type PackageSnapshot struct {
 type MacOSPref struct {
 	Domain string `json:"domain"`
 	Key    string `json:"key"`
-	Type   string `json:"type,omitempty"`
+	Type   string `json:"type"`
 	Value  string `json:"value"`
 	Desc   string `json:"desc"`
 }

internal/ui/snapshot_editor.go

@@ -791,7 +791,7 @@ func buildEditedSnapshot(original *snapshot.Snapshot, m *SnapshotEditorModel) *s
 				if pref, ok := originalPrefs[item.name]; ok {
 					edited.MacOSPrefs = append(edited.MacOSPrefs, pref)
 				} else if item.isAdded {
-					dotIdx := strings.Index(item.name, ".")
+					dotIdx := strings.LastIndex(item.name, ".")
 					if dotIdx > 0 {
 						edited.MacOSPrefs = append(edited.MacOSPrefs, snapshot.MacOSPref{
 							Domain: item.name[:dotIdx],

internal/ui/snapshot_editor_test.go

@@ -749,6 +749,34 @@ func TestSnapshotEditorAddMacOSPrefInvalidFormat(t *testing.T) {
 	assert.NotNil(t, cmd)
 }
 
+func TestBuildEditedSnapshotAddedMacOSPrefSplitsOnLastDot(t *testing.T) {
+	snap := makeTestSnapshot()
+	m := NewSnapshotEditor(snap)
+
+	// Simulate user adding com.apple.dock.tilesize=48 — domain contains multiple dots
+	m.tabs[4].items = append(m.tabs[4].items, editorItem{
+		name:     "com.apple.dock.tilesize",
+		value:    "48",
+		selected: true,
+		itemType: editorItemMacOSPref,
+		isAdded:  true,
+	})
+
+	edited := buildEditedSnapshot(snap, &m)
+
+	var added *snapshot.MacOSPref
+	for i := range edited.MacOSPrefs {
+		if edited.MacOSPrefs[i].Key == "tilesize" {
+			added = &edited.MacOSPrefs[i]
+			break
+		}
+	}
+	require.NotNil(t, added, "added pref should appear in result")
+	assert.Equal(t, "com.apple.dock", added.Domain, "domain should be everything before the last dot")
+	assert.Equal(t, "tilesize", added.Key, "key should be the segment after the last dot")
+	assert.Equal(t, "48", added.Value)
+}
+
 func TestSnapshotEditorAddedItemVisualBadge(t *testing.T) {
 	m := NewSnapshotEditor(makeTestSnapshot())
 	m.width = 80