fix: apply remote config shell and macOS prefs during custom install

Three gaps fixed:

1. runCustomInstall now applies remote config shell settings via
   stepRestoreShell when the config includes a shell block, rather than
   always running the generic Oh-My-Zsh prompt.

2. runCustomInstall now applies remote config macos_prefs via
   stepRestoreMacOS when the config includes preferences, rather than
   always falling back to the 26 hardcoded defaults.

3. Snapshot editor macOS Prefs tab now allows manual add via '+'. Input
   format is domain.key=value (e.g. com.apple.dock.tilesize=48); type
   is auto-inferred at apply time. Added prefs are preserved through
   buildEditedSnapshot and included in the uploaded snapshot.

Author: fullstackjam

internal/installer/installer.go

@@ -144,19 +144,48 @@ func runCustomInstall(cfg *config.Config) error {
 		cfg.DotfilesURL = cfg.RemoteConfig.DotfilesRepo
 	}
 
-	if err := stepShell(cfg); err != nil {
-		ui.Error(fmt.Sprintf("Shell setup failed: %v", err))
-		softErrs = append(softErrs, fmt.Errorf("shell: %w", err))
+	if cfg.RemoteConfig.Shell != nil {
+		cfg.SnapshotShell = &config.SnapshotShellConfig{
+			OhMyZsh: cfg.RemoteConfig.Shell.OhMyZsh,
+			Theme:   cfg.RemoteConfig.Shell.Theme,
+			Plugins: cfg.RemoteConfig.Shell.Plugins,
+		}
+		if err := stepRestoreShell(cfg); err != nil {
+			ui.Error(fmt.Sprintf("Shell setup failed: %v", err))
+			softErrs = append(softErrs, fmt.Errorf("shell: %w", err))
+		}
+	} else {
+		if err := stepShell(cfg); err != nil {
+			ui.Error(fmt.Sprintf("Shell setup failed: %v", err))
+			softErrs = append(softErrs, fmt.Errorf("shell: %w", err))
+		}
 	}
 
 	if err := stepDotfiles(cfg); err != nil {
 		ui.Error(fmt.Sprintf("Dotfiles setup failed: %v", err))
 		softErrs = append(softErrs, fmt.Errorf("dotfiles: %w", err))
 	}
 
-	if err := stepMacOS(cfg); err != nil {
-		ui.Error(fmt.Sprintf("macOS configuration failed: %v", err))
-		softErrs = append(softErrs, fmt.Errorf("macos: %w", err))
+	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,
+			}
+		}
+		if err := stepRestoreMacOS(cfg); err != nil {
+			ui.Error(fmt.Sprintf("macOS configuration failed: %v", err))
+			softErrs = append(softErrs, fmt.Errorf("macos: %w", err))
+		}
+	} else {
+		if err := stepMacOS(cfg); err != nil {
+			ui.Error(fmt.Sprintf("macOS configuration failed: %v", err))
+			softErrs = append(softErrs, fmt.Errorf("macos: %w", err))
+		}
 	}
 
 	if err := stepPostInstall(cfg); err != nil {

internal/ui/snapshot_editor.go

@@ -24,6 +24,7 @@ const (
 type editorItem struct {
 	name        string
 	description string
+	value       string // for macOS pref items: the raw preference value
 	selected    bool
 	itemType    editorItemType
 	isAdded     bool // true = user added this, not from original snapshot
@@ -192,11 +193,6 @@ func (m SnapshotEditorModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			m = m.withFilteredItems()
 
 		case msg.String() == "+":
-			// Block manual add on macOS Prefs tab (prefs require domain.key structure)
-			if m.tabs[m.activeTab].itemType == editorItemMacOSPref {
-				m.toastMessage = "Cannot manually add macOS prefs"
-				return m, editorToastClearCmd()
-			}
 			m.addMode = true
 			m.addInput = ""
 
@@ -321,6 +317,43 @@ func (m SnapshotEditorModel) updateAddMode(msg tea.KeyMsg) (tea.Model, tea.Cmd)
 		return m, nil
 	case "enter":
 		if m.addInput != "" {
+			if m.tabs[m.activeTab].itemType == editorItemMacOSPref {
+				// Expect "domain.key=value" format
+				eqIdx := strings.Index(m.addInput, "=")
+				if eqIdx > 0 {
+					domainKey := m.addInput[:eqIdx]
+					value := m.addInput[eqIdx+1:]
+					if strings.Contains(domainKey, ".") && value != "" {
+						tab := &m.tabs[m.activeTab]
+						duplicate := false
+						for _, item := range tab.items {
+							if item.name == domainKey {
+								duplicate = true
+								break
+							}
+						}
+						if !duplicate {
+							tab.items = append(tab.items, editorItem{
+								name:        domainKey,
+								description: fmt.Sprintf("= %s", value),
+								value:       value,
+								selected:    true,
+								itemType:    editorItemMacOSPref,
+								isAdded:     true,
+							})
+							m.toastMessage = fmt.Sprintf("+ Added %s", domainKey)
+							m.addMode = false
+							m.addInput = ""
+							m.cursor = len(tab.items) - 1
+							return m, editorToastClearCmd()
+						}
+					}
+				}
+				m.toastMessage = "Format: domain.key=value (e.g. com.apple.dock.tilesize=48)"
+				m.addMode = false
+				m.addInput = ""
+				return m, editorToastClearCmd()
+			}
 			tab := &m.tabs[m.activeTab]
 			// Check for duplicates
 			duplicate := false
@@ -410,7 +443,11 @@ func (m SnapshotEditorModel) View() string {
 		lines = append(lines, "")
 		tabName := m.tabs[m.activeTab].name
 		lines = append(lines, activeTabStyle.Render(fmt.Sprintf("Add to %s: %s▌", tabName, m.addInput)))
-		lines = append(lines, descStyle.Render("  Type a package name and press Enter to add, Esc to cancel"))
+		if m.tabs[m.activeTab].itemType == editorItemMacOSPref {
+			lines = append(lines, descStyle.Render("  Format: domain.key=value (e.g. com.apple.dock.tilesize=48) · Enter to add, Esc to cancel"))
+		} else {
+			lines = append(lines, descStyle.Render("  Type a package name and press Enter to add, Esc to cancel"))
+		}
 		lines = append(lines, "")
 	}
 
@@ -753,6 +790,15 @@ func buildEditedSnapshot(original *snapshot.Snapshot, m *SnapshotEditorModel) *s
 			case editorItemMacOSPref:
 				if pref, ok := originalPrefs[item.name]; ok {
 					edited.MacOSPrefs = append(edited.MacOSPrefs, pref)
+				} else if item.isAdded {
+					dotIdx := strings.Index(item.name, ".")
+					if dotIdx > 0 {
+						edited.MacOSPrefs = append(edited.MacOSPrefs, snapshot.MacOSPref{
+							Domain: item.name[:dotIdx],
+							Key:    item.name[dotIdx+1:],
+							Value:  item.value,
+						})
+					}
 				}
 			}
 		}

internal/ui/snapshot_editor_test.go

@@ -702,15 +702,50 @@ func TestSnapshotEditorAddToNpmTab(t *testing.T) {
 	assert.True(t, found, "prettier should be in NPM tab")
 }
 
-func TestSnapshotEditorAddModeBlockedOnMacOSPrefs(t *testing.T) {
+func TestSnapshotEditorAddMacOSPrefActivatesAddMode(t *testing.T) {
 	m := NewSnapshotEditor(makeTestSnapshot())
 	m.activeTab = 4 // macOS Prefs tab
 
-	result, cmd := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("+")})
+	result, _ := m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("+")})
 	updated := result.(SnapshotEditorModel)
 
-	assert.False(t, updated.addMode, "add mode should not activate on macOS Prefs tab")
-	assert.Contains(t, updated.toastMessage, "Cannot manually add macOS prefs")
+	assert.True(t, updated.addMode, "add mode should activate on macOS Prefs tab")
+}
+
+func TestSnapshotEditorAddMacOSPrefValidFormat(t *testing.T) {
+	m := NewSnapshotEditor(makeTestSnapshot())
+	m.activeTab = 4 // macOS Prefs tab
+	m.addMode = true
+	m.addInput = "com.apple.dock.tilesize=64"
+
+	result, cmd := m.Update(tea.KeyMsg{Type: tea.KeyEnter})
+	updated := result.(SnapshotEditorModel)
+
+	assert.False(t, updated.addMode)
+	assert.NotNil(t, cmd)
+	found := false
+	for _, item := range updated.tabs[4].items {
+		if item.name == "com.apple.dock.tilesize" {
+			found = true
+			assert.Equal(t, "64", item.value)
+			assert.True(t, item.isAdded)
+			assert.Equal(t, editorItemMacOSPref, item.itemType)
+		}
+	}
+	assert.True(t, found, "pref should be added to macOS Prefs tab")
+}
+
+func TestSnapshotEditorAddMacOSPrefInvalidFormat(t *testing.T) {
+	m := NewSnapshotEditor(makeTestSnapshot())
+	m.activeTab = 4 // macOS Prefs tab
+	m.addMode = true
+	m.addInput = "invalid-no-equals"
+
+	result, cmd := m.Update(tea.KeyMsg{Type: tea.KeyEnter})
+	updated := result.(SnapshotEditorModel)
+
+	assert.False(t, updated.addMode)
+	assert.Contains(t, updated.toastMessage, "Format:")
 	assert.NotNil(t, cmd)
 }