ADR 0117: Preserve the Windows taskbar entry for native minimize

• Status: Accepted (amended by ADR 0123)
• Date: 2026-08-24
• Deciders: PI-Desktop core
• Related: D216, D252, D256, E2E-124, ADR 0078, ADR 0123

Context

The tray-resident minimize decision in D216 hides the main window from the operating system's window list. On Windows, clicking the taskbar button of the focused window is a native minimize/restore toggle. Electron reports the minimize half of that toggle through the main window's minimize event. The current handler then calls window.hide(), which removes the taskbar entry and leaves only the tray icon as a restore path.

Decision

1. On Windows, the main window's native minimize event is not converted to window.hide(). The OS completes the minimize, so the main window remains represented by its taskbar entry.
2. The renderer-drawn Windows minimize button and the Windows native-menu minimize action use the same native minimize transition. Linux uses that transition for its renderer and native-menu minimize actions as well. The macOS native minimize event remains tray-resident.
3. The existing restore path continues to restore and focus the same window. Clicking the taskbar entry while the window is merely covered therefore keeps its existing bring-to-front behavior; no new IPC, storage, or host protocol contract is needed.

Consequences

• Windows has one native taskbar minimize model for both the OS taskbar toggle and the explicit in-app minimize action.
• Windows/Linux taskbar-minimized windows remain reachable from the taskbar; close-to-tray windows remain reachable from the resident tray icon.
• Background work and window bounds persistence are unchanged.