Replace EventLogger with typed AnalyticsManager using PostHog

Complete analytics overhaul: delete EventLogger.swift, create Analytics.swift
with typed event enum (~45 events), screen tracking, super properties
(theme, icon pack, voting layout, etc.), session replay with kill switch,
autocapture, and network telemetry. Replace all 99 call sites across 38 files
with compiler-enforced typed events in object_action naming convention.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Shared/Views/CustomizeView/SubViews/ThemePickerView.swift

@@ -71,7 +71,7 @@ struct ThemePickerView: View {
             selectedTheme = theme
         }
 
-        EventLogger.log(event: "change_theme_id", withData: ["id": theme.rawValue])
+        AnalyticsManager.shared.track(.themeChanged(themeId: theme.rawValue))
     }
 }