feat: add Cancel and Defaults buttons to Settings

Cancel discards unsaved edits by reloading the saved config; Defaults
loads built-in default values into the form for review before saving.
Extracts the default config into domain.DefaultConfig() so the store
and settings UI share one source of truth.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/domain/config.go

@@ -62,6 +62,25 @@ type Config struct {
 	Theme Theme `json:"theme,omitempty"`
 }
 
+// DefaultConfig returns the built-in default settings. It is the config used
+// when gosentry.json does not yet exist, and is also what the Settings UI
+// offers to restore via its "Defaults" button.
+func DefaultConfig() Config {
+	return Config{
+		JobsDir:               ".",
+		LogsDir:               "logs",
+		MaxLogFiles:           100,
+		MaxLogAgeDays:         30,
+		StartOnLogin:          false,
+		KeepRunningInTray:     true,
+		NotifyOnFailure:       true,
+		ExecutionMode:         ExecutionModeParallel,
+		OverlapPolicy:         OverlapPolicySkip,
+		Theme:                 ThemeDefault,
+		DefaultTimeoutSeconds: 30,
+	}
+}
+
 // JobsFile is the on-disk shape of jobs.json. Wrapping the slice in a top-level
 // object leaves room for future metadata without breaking the basic file format.
 type JobsFile struct {

src/storage/store.go

@@ -68,20 +68,7 @@ func (s *Store) SaveJobs(jobs []domain.Job) error {
 func loadOrCreateConfig(paths Paths) (domain.Config, error) {
 	// Defaults favor a portable installation: settings and jobs begin next to the
 	// executable, while logs are grouped under a dedicated subdirectory.
-	config := domain.Config{
-		JobsDir:           ".",
-		LogsDir:           "logs",
-		MaxLogFiles:       100,
-		MaxLogAgeDays:     30,
-		StartOnLogin:      false,
-		KeepRunningInTray: true,
-		NotifyOnFailure:   true,
-		ExecutionMode:     domain.ExecutionModeParallel,
-		OverlapPolicy:     domain.OverlapPolicySkip,
-		Theme:             domain.ThemeDefault,
-
-		DefaultTimeoutSeconds: 30,
-	}
+	config := domain.DefaultConfig()
 
 	if _, err := os.Stat(paths.ConfigPath); errors.Is(err, os.ErrNotExist) {
 		return config, writeJSON(paths.ConfigPath, config)

src/ui/settings_view.go

@@ -35,6 +35,9 @@ func settingsView(w fyne.Window, svc *app.Service) fyne.CanvasObject {
 	// when something differs. It is defined below (once Save and every field
 	// exist) but declared here so the field change handlers can reference it.
 	var updateSaveState func()
+	// loadFields populates every form control from the given config. It backs
+	// both the initial load and the Cancel/Defaults buttons below.
+	var loadFields func(domain.Config)
 	startOnLogin := widget.NewCheck("Start on login", nil)
 	startOnLogin.SetChecked(store.Config.StartOnLogin)
 	autostartStatus := widget.NewLabel("")
@@ -188,6 +191,38 @@ func settingsView(w fyne.Window, svc *app.Service) fyne.CanvasObject {
 	}
 	updateSaveState()
 
+	// loadFields populates every form control from a config without saving it,
+	// backing both the Cancel button (reload the saved config, discarding edits)
+	// and the Defaults button (load the built-in defaults for review before
+	// Save is clicked).
+	loadFields = func(c domain.Config) {
+		startOnLogin.SetChecked(c.StartOnLogin)
+		minimizeToTray.SetChecked(c.KeepRunningInTray)
+		notifications.SetChecked(c.NotifyOnFailure)
+		themeSelect.SetSelected(themeLabel(c.Theme))
+		applyTheme(fyne.CurrentApp(), themeFromLabel(themeSelect.Selected))
+		executionModeSelect.SetSelected(string(c.ExecutionMode))
+		overlapPolicySelect.SetSelected(string(c.OverlapPolicy))
+		defaultTimeout.SetText(strconv.Itoa(c.DefaultTimeoutSeconds))
+		jobsDir.SetText(c.JobsDir)
+		logsDir.SetText(c.LogsDir)
+		maxLogFiles.SetText(strconv.Itoa(c.MaxLogFiles))
+		maxLogAgeDays.SetText(strconv.Itoa(c.MaxLogAgeDays))
+		if startOnLogin.Checked != store.Config.StartOnLogin {
+			autostartStatus.SetText("Pending: save settings to apply")
+		} else {
+			refreshAutostartStatus()
+		}
+		settingsStatus.SetText("")
+		updateSaveState()
+	}
+	cancelSettings := widget.NewButtonWithIcon("Cancel", theme.CancelIcon(), func() {
+		loadFields(store.Config)
+	})
+	restoreDefaults := widget.NewButtonWithIcon("Defaults", theme.MediaReplayIcon(), func() {
+		loadFields(domain.DefaultConfig())
+	})
+
 	// The form is split into two columns so a wide window uses its horizontal
 	// space instead of stretching into one tall strip. The left column holds the
 	// toggles (Application, Queue); the right holds the editable Storage fields and
@@ -241,10 +276,10 @@ func settingsView(w fyne.Window, svc *app.Service) fyne.CanvasObject {
 	return container.NewVScroll(container.NewPadded(container.NewVBox(
 		container.NewGridWithColumns(2, leftColumn, rightColumn),
 		widget.NewSeparator(),
-		// Save button and its status share one row so an empty status (the common
-		// case) does not leave a blank line above the separator. The status appears
-		// beside the button once a save reports a result.
-		container.NewHBox(saveSettings, settingsStatus),
+		// Save/Cancel/Defaults share one row with the status so an empty status
+		// (the common case) does not leave a blank line above the separator. The
+		// status appears beside the buttons once a save reports a result.
+		container.NewHBox(saveSettings, cancelSettings, restoreDefaults, settingsStatus),
 	)))
 }