Win Finder v0.1.5

Fix Sparkle automatic update checks never firing

SPUStandardUpdaterController was stored as a plain let on the App value
type, so SwiftUI could tear it down and recreate it between evaluations,
destroying the scheduled-check timer each time. Moving ownership to
AppDelegate (a reference type with guaranteed app lifetime) keeps the
scheduler alive. Also add SUScheduledCheckInterval=3600 to Info.plist
as a belt-and-suspenders fallback.

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