Add iPhone target with shared data layer and persistent cache

Two-target restructure: shared sources (models, services, settings,
extensions, team logos) move into Shared/, consumed by both the
existing macOS menu bar app and a new iOS app. MainService no longer
imports AppKit — platform code attaches via a MainServiceObserver
protocol (MacObserverAdapter wires back to MenuManager / StatusItemManager
/ NotificationManager).

iPhone app is a single SwiftUI page mirroring the macOS menu (playoff
round + yesterday/today/tomorrow), with a gear-icon settings sheet
(display option + IndieAbout for license/changelog). Persistent JSON
snapshot in Application Support paints last-known data on cold launch;
"Updated …" header escalates secondary → orange (>5min) → red (>30min)
so staleness is visually unmistakable. Foreground polling, scenePhase
refresh, and pull-to-refresh; no notifications on iOS in v1.

Shared/Extensions/Date+etCalendar.swift

@@ -0,0 +1,16 @@
+//
+// Date+etCalendar.swift
+// IceGlass
+//
+// Copyright 2026 Rouslan Zenetl. All Rights Reserved.
+//
+
+import Foundation
+
+extension Date {
+    static func etCalendar() -> Calendar {
+        var calendar = Calendar.current
+        calendar.timeZone = Date.easternTimeZone
+        return calendar
+    }
+}