feat(tray): double-click / click tray icon to show or hide main window

[gaursomya777-dev]

What problem does it solve?

On Windows/Linux, the system tray icon only opens a context menu. Users who enable "close to tray" expect a familiar double-click (or single-click) on the tray icon to show/hide the main window — without hunting the menu every time.

Proposed solution

Wire the tray icon click handlers in tray.ts:

1. Double-click (Windows) / click (Linux where double-click is unreliable): toggle show/focus vs hide when close-to-tray is enabled.
2. Keep the existing context menu for New Chat / Recent / Quit / etc.
3. macOS: leave menu-bar click behavior alone unless we can match platform norms (status item usually single-click menu).

Scope

Desktop main-process tray module only (packages/desktop/src/process/utils/tray.ts). Small, self-contained UX fix.

Willing to implement it yourself?

Yes — please convert to a bonus issue assigned to me for the AionUi × Kimi campaign if accepted.

[github-actions[bot]]

Thanks for posting! @IceyLiu will take a look soon. / 感谢发帖！@IceyLiu 会尽快跟进。