Wire the Windows systray's double-click to ShowWindow(), matching the
Windows-native convention for tray apps. The Wails v3 systray dispatches
WM_LBUTTONDBLCLK to the doubleClickHandler, so OnDoubleClick fires; left-
and right-click continue to open the menu. macOS/Linux are unchanged.
Wails v3 does not auto-show the tray menu on left-click on Windows — its
default left-click handler only logs and does nothing visible, so only
right-click opened the menu. macOS (NSStatusItem) and Linux
(StatusNotifierItem host) give us click→menu natively.
Add a build-tag-split bindTrayClick: the Windows variant wires
OnClick→OpenMenu (the same menu.ShowAt path right-click uses), while the
macOS/Linux variant stays a no-op — binding OnClick→OpenMenu on macOS
freezes the tray via NSStatusItem's blocking mouseDown on the main GCD
queue (the reason commit c77e5cef8 reverted the earlier wiring).
Zoltán Papp