restore standard window controls, minimize-to-tray, close-exits

- Restore default FormBorderStyle (resizable with min/max/close buttons)
- Minimize button hides to tray (WindowState=Minimized -> Hide())
- Close button and tray Exit both call Shutdown() then close normally
- Tray Show/DoubleClick restores window from tray

win/gatuna-client/MainForm.cs

@@ -17,9 +17,6 @@ public partial class MainForm : Form
         Text = "gatuna";
         Width = 520;
         Height = 380;
-        FormBorderStyle = FormBorderStyle.FixedSingle;
-        MaximizeBox = false;
-        MinimizeBox = false;
         StartPosition = FormStartPosition.CenterScreen;
         InitializeComponents();
 
@@ -146,14 +143,19 @@ public partial class MainForm : Form
         }
     }
 
+    protected override void OnResize(EventArgs e)
+    {
+        base.OnResize(e);
+        if (WindowState == FormWindowState.Minimized)
+        {
+            Hide();
+            WindowState = FormWindowState.Normal;
+        }
+    }
+
     protected override void OnFormClosing(FormClosingEventArgs e)
     {
-        if (e.CloseReason == CloseReason.UserClosing)
-        {
-            e.Cancel = true;
-            Hide();
-            return;
-        }
+        Shutdown();
         base.OnFormClosing(e);
     }
 

win/gatuna-client/Program.cs

@@ -20,18 +20,19 @@ static class Program
         tray.ContextMenuStrip.Items.Add("Show", null, (_, _) =>
         {
             form.Show();
+            form.WindowState = FormWindowState.Normal;
             form.Activate();
         });
         tray.ContextMenuStrip.Items.Add("-");
         tray.ContextMenuStrip.Items.Add("Exit", null, (_, _) =>
         {
-            form.Shutdown();
             tray.Visible = false;
-            Application.Exit();
+            form.Close();
         });
         tray.DoubleClick += (_, _) =>
         {
             form.Show();
+            form.WindowState = FormWindowState.Normal;
             form.Activate();
         };