chore: modernize Go code with stdlib improvements

internal/claude/manifest.go

@@ -157,8 +157,7 @@ func listMarkdownFilesFS(fsys fs.FS, dir string) []string {
 
 	var result []string
 	for _, entry := range entries {
-		if !entry.IsDir() && strings.HasSuffix(entry.Name(), ".md") {
-			name := strings.TrimSuffix(entry.Name(), ".md")
+		if name, ok := strings.CutSuffix(entry.Name(), ".md"); !entry.IsDir() && ok {
 			result = append(result, name)
 		}
 	}

internal/tui/model.go

@@ -2,7 +2,9 @@
 package tui
 
 import (
-	"sort"
+	"cmp"
+	"maps"
+	"slices"
 	"strings"
 
 	tea "github.com/charmbracelet/bubbletea"
@@ -252,15 +254,6 @@ func firstScope(m map[claude.Scope]bool) claude.Scope {
 	return claude.ScopeNone
 }
 
-// copyMap creates a shallow copy of a scope map.
-func copyMap(m map[claude.Scope]bool) map[claude.Scope]bool {
-	result := make(map[claude.Scope]bool, len(m))
-	for k, v := range m {
-		result[k] = v
-	}
-	return result
-}
-
 // MainState holds state for the main two-pane view.
 type MainState struct {
 	pendingOps      map[string]Operation
@@ -532,18 +525,14 @@ func processInstalledPlugin(p claude.InstalledPlugin, allScopes claude.ScopeStat
 // sortAndGroupByMarketplace sorts and groups plugins by marketplace with headers.
 func sortAndGroupByMarketplace(byMarketplace map[string][]PluginState) []PluginState {
 	// Sort marketplace names
-	marketplaces := make([]string, 0, len(byMarketplace))
-	for marketplace := range byMarketplace {
-		marketplaces = append(marketplaces, marketplace)
-	}
-	sort.Strings(marketplaces)
+	marketplaces := slices.Sorted(maps.Keys(byMarketplace))
 
 	// Build result with headers
 	var result []PluginState
 	for _, marketplace := range marketplaces {
 		plugins := byMarketplace[marketplace]
-		sort.Slice(plugins, func(i, j int) bool {
-			return strings.ToLower(plugins[i].Name) < strings.ToLower(plugins[j].Name)
+		slices.SortFunc(plugins, func(a, b PluginState) int {
+			return cmp.Compare(strings.ToLower(a.Name), strings.ToLower(b.Name))
 		})
 		result = append(result, PluginState{
 			Name:          marketplace,
@@ -613,7 +602,7 @@ func (m *Model) openScopeDialog(pluginID string, installedScopes map[claude.Scop
 	m.mode = ModeScopeDialog
 	m.main.scopeDialog = scopeDialogState{
 		pluginID:       pluginID,
-		originalScopes: copyMap(installedScopes),
+		originalScopes: maps.Clone(installedScopes),
 	}
 	// Initialize checkboxes from current installed scopes (presence, not enabled value)
 	_, m.main.scopeDialog.scopes[0] = installedScopes[claude.ScopeUser]

internal/tui/update.go

@@ -1,10 +1,12 @@
 package tui
 
 import (
+	"cmp"
 	"fmt"
 	"io/fs"
+	"maps"
 	"os"
-	"sort"
+	"slices"
 	"strings"
 
 	tea "github.com/charmbracelet/bubbletea"
@@ -225,15 +227,15 @@ func (m *Model) applyScopeDialogDelta() {
 		m.main.pendingOps[dialog.pluginID] = Operation{
 			PluginID:       dialog.pluginID,
 			Scopes:         uninstallScopes,
-			OriginalScopes: copyMap(original),
+			OriginalScopes: maps.Clone(original),
 			Type:           OpUninstall,
 		}
 	case len(installScopes) > 0 && len(uninstallScopes) == 0:
 		// Pure install (adding scopes)
 		m.main.pendingOps[dialog.pluginID] = Operation{
 			PluginID:       dialog.pluginID,
 			Scopes:         installScopes,
-			OriginalScopes: copyMap(original),
+			OriginalScopes: maps.Clone(original),
 			Type:           OpInstall,
 		}
 	default:
@@ -244,7 +246,7 @@ func (m *Model) applyScopeDialogDelta() {
 			PluginID:        dialog.pluginID,
 			Scopes:          installScopes,
 			UninstallScopes: uninstallScopes,
-			OriginalScopes:  copyMap(original),
+			OriginalScopes:  maps.Clone(original),
 			Type:            OpScopeChange,
 		}
 	}
@@ -297,15 +299,15 @@ func (m *Model) moveDown() {
 // pageUp moves up by a page.
 func (m *Model) pageUp() {
 	pageSize := m.getPageSize()
-	for i := 0; i < pageSize; i++ {
+	for range pageSize {
 		m.moveUp()
 	}
 }
 
 // pageDown moves down by a page.
 func (m *Model) pageDown() {
 	pageSize := m.getPageSize()
-	for i := 0; i < pageSize; i++ {
+	for range pageSize {
 		m.moveDown()
 	}
 }
@@ -358,10 +360,7 @@ func (m *Model) ensureVisible() {
 	if m.listOffset < 0 {
 		m.listOffset = 0
 	}
-	maxOffset := len(m.plugins) - pageSize
-	if maxOffset < 0 {
-		maxOffset = 0
-	}
+	maxOffset := max(len(m.plugins)-pageSize, 0)
 	if m.listOffset > maxOffset {
 		m.listOffset = maxOffset
 	}
@@ -400,7 +399,7 @@ func (m *Model) selectForInstall(scope claude.Scope) {
 			m.main.pendingOps[plugin.ID] = Operation{
 				PluginID:       plugin.ID,
 				Scopes:         []claude.Scope{scope},
-				OriginalScopes: copyMap(plugin.InstalledScopes),
+				OriginalScopes: maps.Clone(plugin.InstalledScopes),
 				Type:           OpMigrate,
 			}
 			continue
@@ -455,7 +454,7 @@ func (m *Model) computeNextToggleOp(plugin *PluginState) *Operation {
 			return &Operation{
 				PluginID:       plugin.ID,
 				Scopes:         []claude.Scope{},
-				OriginalScopes: copyMap(plugin.InstalledScopes),
+				OriginalScopes: maps.Clone(plugin.InstalledScopes),
 				Type:           OpUninstall,
 			}
 		}
@@ -473,7 +472,7 @@ func (m *Model) firstToggleOp(plugin *PluginState, scope claude.Scope) *Operatio
 		return &Operation{
 			PluginID:       plugin.ID,
 			Scopes:         []claude.Scope{scope},
-			OriginalScopes: copyMap(plugin.InstalledScopes),
+			OriginalScopes: maps.Clone(plugin.InstalledScopes),
 			Type:           OpMigrate,
 		}
 	}
@@ -514,7 +513,7 @@ func (m *Model) selectForUninstall() {
 		m.main.pendingOps[plugin.ID] = Operation{
 			PluginID:       plugin.ID,
 			Scopes:         []claude.Scope{plugin.SingleScope()},
-			OriginalScopes: copyMap(plugin.InstalledScopes),
+			OriginalScopes: maps.Clone(plugin.InstalledScopes),
 			Type:           OpUninstall,
 		}
 	}
@@ -587,7 +586,7 @@ func (m *Model) startExecution() (tea.Model, tea.Cmd) {
 	}
 
 	// Sort operations: uninstalls first, then migrations, then scope changes, then updates, then installs, then enable/disable
-	sort.Slice(m.progress.operations, func(i, j int) bool {
+	slices.SortFunc(m.progress.operations, func(a, b Operation) int {
 		typeOrder := map[OperationType]int{
 			OpUninstall:   0,
 			OpMigrate:     1,
@@ -597,14 +596,7 @@ func (m *Model) startExecution() (tea.Model, tea.Cmd) {
 			OpEnable:      5,
 			OpDisable:     6,
 		}
-		orderI := typeOrder[m.progress.operations[i].Type]
-		orderJ := typeOrder[m.progress.operations[j].Type]
-
-		// If same order, maintain stable sort (don't swap)
-		if orderI == orderJ {
-			return false
-		}
-		return orderI < orderJ
+		return cmp.Compare(typeOrder[a.Type], typeOrder[b.Type])
 	})
 
 	m.progress.currentIdx = 0
@@ -943,11 +935,11 @@ func (m *Model) handleMouse(msg tea.MouseMsg) (tea.Model, tea.Cmd) {
 	case tea.MouseButtonLeft:
 		m.handleMouseClick(msg)
 	case tea.MouseButtonWheelUp:
-		for i := 0; i < wheelScrollSpeed; i++ {
+		for range wheelScrollSpeed {
 			m.moveUp()
 		}
 	case tea.MouseButtonWheelDown:
-		for i := 0; i < wheelScrollSpeed; i++ {
+		for range wheelScrollSpeed {
 			m.moveDown()
 		}
 	}
@@ -1031,12 +1023,12 @@ func (m *Model) extractNonHeaderPlugins() []PluginState {
 func applySortMode(plugins []PluginState, sortMode SortMode) {
 	switch sortMode {
 	case SortByNameAsc:
-		sort.Slice(plugins, func(i, j int) bool {
-			return strings.ToLower(plugins[i].Name) < strings.ToLower(plugins[j].Name)
+		slices.SortFunc(plugins, func(a, b PluginState) int {
+			return cmp.Compare(strings.ToLower(a.Name), strings.ToLower(b.Name))
 		})
 	case SortByNameDesc:
-		sort.Slice(plugins, func(i, j int) bool {
-			return strings.ToLower(plugins[i].Name) > strings.ToLower(plugins[j].Name)
+		slices.SortFunc(plugins, func(a, b PluginState) int {
+			return cmp.Compare(strings.ToLower(b.Name), strings.ToLower(a.Name))
 		})
 	case SortByScope:
 		sortByScope(plugins)
@@ -1053,23 +1045,21 @@ func sortByScope(plugins []PluginState) {
 		claude.ScopeUser:    2,
 		claude.ScopeNone:    3,
 	}
-	sort.Slice(plugins, func(i, j int) bool {
-		orderI := scopeOrder[plugins[i].SingleScope()]
-		orderJ := scopeOrder[plugins[j].SingleScope()]
-		if orderI != orderJ {
-			return orderI < orderJ
+	slices.SortFunc(plugins, func(a, b PluginState) int {
+		if c := cmp.Compare(scopeOrder[a.SingleScope()], scopeOrder[b.SingleScope()]); c != 0 {
+			return c
 		}
-		return strings.ToLower(plugins[i].Name) < strings.ToLower(plugins[j].Name)
+		return cmp.Compare(strings.ToLower(a.Name), strings.ToLower(b.Name))
 	})
 }
 
 // sortByMarketplace sorts plugins by marketplace name.
 func sortByMarketplace(plugins []PluginState) {
-	sort.Slice(plugins, func(i, j int) bool {
-		if plugins[i].Marketplace != plugins[j].Marketplace {
-			return plugins[i].Marketplace < plugins[j].Marketplace
+	slices.SortFunc(plugins, func(a, b PluginState) int {
+		if c := cmp.Compare(a.Marketplace, b.Marketplace); c != 0 {
+			return c
 		}
-		return strings.ToLower(plugins[i].Name) < strings.ToLower(plugins[j].Name)
+		return cmp.Compare(strings.ToLower(a.Name), strings.ToLower(b.Name))
 	})
 }
 
@@ -1157,7 +1147,7 @@ func rebuildWithGroupHeaders(plugins []PluginState, sortMode SortMode) []PluginS
 			}
 			byGroup[group] = append(byGroup[group], p)
 		}
-		sort.Strings(groups) // Sort groups alphabetically
+		slices.Sort(groups) // Sort groups alphabetically
 		for _, group := range groups {
 			result = append(result, PluginState{
 				Name:          group,
@@ -1167,12 +1157,12 @@ func rebuildWithGroupHeaders(plugins []PluginState, sortMode SortMode) []PluginS
 			// Sort within group by current sort mode
 			groupPlugins := byGroup[group]
 			if sortMode == SortByNameDesc {
-				sort.Slice(groupPlugins, func(i, j int) bool {
-					return strings.ToLower(groupPlugins[i].Name) > strings.ToLower(groupPlugins[j].Name)
+				slices.SortFunc(groupPlugins, func(a, b PluginState) int {
+					return cmp.Compare(strings.ToLower(b.Name), strings.ToLower(a.Name))
 				})
 			} else {
-				sort.Slice(groupPlugins, func(i, j int) bool {
-					return strings.ToLower(groupPlugins[i].Name) < strings.ToLower(groupPlugins[j].Name)
+				slices.SortFunc(groupPlugins, func(a, b PluginState) int {
+					return cmp.Compare(strings.ToLower(a.Name), strings.ToLower(b.Name))
 				})
 			}
 			result = append(result, groupPlugins...)

internal/tui/view.go

@@ -1,8 +1,10 @@
 package tui
 
 import (
+	"cmp"
 	"fmt"
-	"sort"
+	"maps"
+	"slices"
 	"strconv"
 	"strings"
 	"time"
@@ -73,10 +75,7 @@ func (m *Model) renderList(styles Styles) string {
 
 	// Calculate visible range
 	start := m.listOffset
-	end := start + visibleHeight
-	if end > len(plugins) {
-		end = len(plugins)
-	}
+	end := min(start+visibleHeight, len(plugins))
 
 	for i := start; i < end; i++ {
 		plugin := plugins[i]
@@ -189,7 +188,7 @@ func (m *Model) getScopeIndicator(plugin PluginState, styles Styles) string {
 
 // applyScopeDelta returns a new scope set with uninstalls removed and installs added.
 func applyScopeDelta(base map[claude.Scope]bool, uninstall, install []claude.Scope) map[claude.Scope]bool {
-	result := copyMap(base)
+	result := maps.Clone(base)
 	for _, s := range uninstall {
 		delete(result, s)
 	}
@@ -478,19 +477,13 @@ func (m *Model) renderDoc(styles Styles) string {
 	visibleHeight := m.height - 4 // Account for header and help bar
 
 	// Clamp scroll position
-	maxScroll := len(lines) - visibleHeight
-	if maxScroll < 0 {
-		maxScroll = 0
-	}
+	maxScroll := max(len(lines)-visibleHeight, 0)
 	if m.doc.scroll > maxScroll {
 		m.doc.scroll = maxScroll
 	}
 
 	// Get visible lines
-	endIdx := m.doc.scroll + visibleHeight
-	if endIdx > len(lines) {
-		endIdx = len(lines)
-	}
+	endIdx := min(m.doc.scroll+visibleHeight, len(lines))
 	visibleLines := lines[m.doc.scroll:endIdx]
 	content := strings.Join(visibleLines, "\n")
 
@@ -527,7 +520,7 @@ func (m *Model) renderConfirmation(styles Styles) string {
 
 	// Sort operations by type for consistent display
 	// Uninstalls, then migrations, then updates, then installs, then enables, then disables
-	sort.Slice(operations, func(i, j int) bool {
+	slices.SortFunc(operations, func(a, b Operation) int {
 		typeOrder := map[OperationType]int{
 			OpUninstall: 0,
 			OpMigrate:   1,
@@ -536,7 +529,7 @@ func (m *Model) renderConfirmation(styles Styles) string {
 			OpEnable:    4,
 			OpDisable:   5,
 		}
-		return typeOrder[operations[i].Type] < typeOrder[operations[j].Type]
+		return cmp.Compare(typeOrder[a.Type], typeOrder[b.Type])
 	})
 
 	for _, op := range operations {
@@ -795,7 +788,7 @@ func (m *Model) renderScopeDialog(styles Styles) string {
 	lines = append(lines, styles.Header.Render(" Scopes for "+dialog.pluginID+" "))
 	lines = append(lines, "")
 
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		checkbox := "[ ]"
 		if dialog.scopes[i] {
 			checkbox = "[x]"
@@ -841,24 +834,12 @@ func (m *Model) renderConfig(styles Styles) string {
 	header := styles.Header.Render(" " + m.config.title + " ")
 
 	// Content area
-	contentHeight := m.height - 4 // Account for header and help bar
-	if contentHeight < 1 {
-		contentHeight = 1
-	}
+	contentHeight := max(m.height-4, 1) // Account for header and help bar
 
 	// Split content into lines and apply scroll
 	lines := strings.Split(m.config.content, "\n")
-	startLine := m.config.scroll
-	if startLine >= len(lines) {
-		startLine = len(lines) - 1
-		if startLine < 0 {
-			startLine = 0
-		}
-	}
-	endLine := startLine + contentHeight
-	if endLine > len(lines) {
-		endLine = len(lines)
-	}
+	startLine := min(m.config.scroll, max(len(lines)-1, 0))
+	endLine := min(startLine+contentHeight, len(lines))
 
 	visibleLines := lines[startLine:endLine]
 	content := strings.Join(visibleLines, "\n")