The app.MinSize and app.MaxSize options restricts the window size:
w := app.NewWindow(
app.Size(unit.Dp(600), unit.Dp(596)),
app.MinSize(unit.Dp(600), unit.Dp(596)),
app.MaxSize(unit.Dp(600), unit.Dp(596)),
app.Title(APPNAME),
)
Signed-off-by: Jason <sourcehut@sweatyballs.es>