Add CGO build tags for systray and update flake version

- Add //go:build cgo tag to systray.go for CGO-enabled builds
- Add systray_nocgo.go stub for non-CGO cross-platform builds
- Update flake.nix version to 0.7.1
- Allows cross-compilation without CGO (systray disabled)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: timlinux

flake.nix

@@ -10,7 +10,7 @@
     flake-utils.lib.eachDefaultSystem (system:
       let
         pkgs = nixpkgs.legacyPackages.${system};
-        version = "0.1.0";
+        version = "0.7.1";
 
         # MkDocs with Material theme for documentation
         mkdocsEnv = pkgs.python3.withPackages (ps: with ps; [

internal/systray/systray.go

@@ -1,3 +1,5 @@
+//go:build cgo
+
 package systray
 
 import (

internal/systray/systray_nocgo.go

@@ -0,0 +1,57 @@
+//go:build !cgo
+
+package systray
+
+import (
+	"fmt"
+	"time"
+)
+
+// Stub implementation for non-CGO builds
+// System tray functionality requires CGO and is not available in this build.
+
+type TrayState int
+
+const (
+	StateIdle TrayState = iota
+	StateRecording
+	StatePaused
+	StateProcessing
+)
+
+type RecordingInfo struct {
+	Monitor   string
+	StartTime time.Time
+	IsPaused  bool
+}
+
+type Manager struct{}
+
+func New() *Manager {
+	return &Manager{}
+}
+
+func (m *Manager) StartChan() <-chan struct{}        { return make(chan struct{}) }
+func (m *Manager) StopChan() <-chan struct{}         { return make(chan struct{}) }
+func (m *Manager) PauseChan() <-chan struct{}        { return make(chan struct{}) }
+func (m *Manager) TUIChan() <-chan struct{}          { return make(chan struct{}) }
+func (m *Manager) QuitChan() <-chan struct{}         { return make(chan struct{}) }
+func (m *Manager) OnReady()                          {}
+func (m *Manager) OnExit()                           {}
+func (m *Manager) SetRecordingActive(string, time.Time) {}
+func (m *Manager) SetRecordingPaused()               {}
+func (m *Manager) SetIdle()                          {}
+func (m *Manager) SetProcessing()                    {}
+func (m *Manager) StartRecording() error             { return fmt.Errorf("systray not available: built without CGO") }
+func (m *Manager) StopRecording() error              { return fmt.Errorf("systray not available: built without CGO") }
+func (m *Manager) PauseRecording() error             { return fmt.Errorf("systray not available: built without CGO") }
+func (m *Manager) OpenTUI() error                    { return fmt.Errorf("systray not available: built without CGO") }
+
+func Run() {
+	fmt.Println("System tray not available: this build was compiled without CGO support.")
+	fmt.Println("Use 'kartoza-screencaster' (TUI mode) instead.")
+}
+
+func RunWithHandler() {
+	Run()
+}