feat: initial gosleep-timer implementation

Go TUI sleep timer with modular architecture.
- Config: YAML-based, profile inheritance, auto WM detection
- Engine: timer, executor, stage pipeline (pre→timer→post)
- Modules: workspace (niri/hyprland/kde), media, lock, kill,
  notify, sound, brightness, mute, custom, script
- TUI: bubbletea app with profiles, module toggles, progress bar
- CLI: run, list-profiles, export, import, history, stats
- History: JSONL log with statistics
- QR: config export as ASCII QR

tui/widgets.go

@@ -0,0 +1,104 @@
+package tui
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/charmbracelet/lipgloss"
+)
+
+// ProgressBar renders a progress bar with given width, percent (0.0-1.0)
+func ProgressBar(width int, percent float64, label string) string {
+	if width < 10 {
+		width = 10
+	}
+	filled := int(float64(width) * percent)
+	if filled > width {
+		filled = width
+	}
+	empty := width - filled
+
+	bar := strings.Repeat("█", filled) + strings.Repeat("░", empty)
+	bar = lipgloss.NewStyle().Foreground(lipgloss.Color("#33ccff")).Render(bar)
+
+	pct := fmt.Sprintf("%3d%%", int(percent*100))
+	return fmt.Sprintf("%s %s  %s", pct, bar, label)
+}
+
+// TimerBlock renders the main timer display (HH:MM:SS)
+func TimerBlock(remaining time.Duration) string {
+	totalSec := int(remaining.Seconds())
+	h := totalSec / 3600
+	m := (totalSec % 3600) / 60
+	s := totalSec % 60
+
+	timeStr := fmt.Sprintf("%02d:%02d:%02d", h, m, s)
+	return TimerStyle.Render(timeStr)
+}
+
+// ModuleCheckbox renders a module toggle line
+func ModuleCheckbox(name string, enabled bool, checked bool) string {
+	checkmark := " "
+	if checked {
+		checkmark = "●"
+	}
+	style := InactiveModuleStyle
+	if enabled {
+		style = ActiveModuleStyle
+	}
+	return style.Render(fmt.Sprintf("[ %s ] %s", checkmark, name))
+}
+
+// StatusLine renders a status message
+func StatusLine(msg string, isError bool) string {
+	if isError {
+		return ErrorStyle.Render(msg)
+	}
+	return StatusStyle.Render(msg)
+}
+
+// HelpBar renders the bottom help bar with keybindings
+func HelpBar(items ...string) string {
+	return HelpStyle.Render(strings.Join(items, "  ·  "))
+}
+
+// InputField renders a labeled input field
+func InputField(label, value, placeholder string, focused bool) string {
+	style := LabelStyle
+	borderColor := "#444"
+	if focused {
+		borderColor = "#33ccff"
+	}
+	val := value
+	if val == "" {
+		val = placeholder
+		style = DimmedStyle
+	}
+	inputBox := lipgloss.NewStyle().
+		Border(lipgloss.RoundedBorder()).
+		BorderForeground(lipgloss.Color(borderColor)).
+		Width(30).
+		Render(val)
+
+	return fmt.Sprintf("%s\n%s", style.Render(label), inputBox)
+}
+
+// SelectWidget renders a simple select list
+func SelectWidget(label string, options []string, selected int) string {
+	var b strings.Builder
+	b.WriteString(LabelStyle.Render(label))
+	b.WriteString("\n")
+	for i, opt := range options {
+		if i == selected {
+			b.WriteString(lipgloss.NewStyle().
+				Foreground(lipgloss.Color("#33ccff")).
+				Bold(true).
+				Render("▸ " + opt))
+		} else {
+			b.WriteString("  " + opt)
+		}
+		b.WriteString("\n")
+	}
+	return b.String()
+}