Add WireGuard TUI implementation

- Add Go TUI with bubbletea for WireGuard management
- Implement client CRUD operations with QR code generation
- Add configuration and validation modules
- Install/update scripts for client setup
- Update Makefile to build binaries to bin/ directory
- Add .gitignore for Go projects

internal/tui/screens/interface.go

@@ -0,0 +1,31 @@
+package screens
+
+import (
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+// Screen represents a UI screen (list, add, detail, etc.)
+type Screen interface {
+	Init() tea.Cmd
+	Update(tea.Msg) (Screen, tea.Cmd)
+	View() string
+}
+
+// ClientSelectedMsg is sent when a client is selected from the list
+type ClientSelectedMsg struct {
+	Client ClientWithStatus
+}
+
+// ClientDeletedMsg is sent when a client is successfully deleted
+type ClientDeletedMsg struct {
+	Name string
+}
+
+// CloseDetailScreenMsg signals to close detail screen
+type CloseDetailScreenMsg struct{}
+
+// RestoreCompletedMsg is sent when a restore operation completes
+type RestoreCompletedMsg struct {
+	Err              error
+	SafetyBackupPath string
+}