[Kimlimp]

Summary

Avoids redundant sorting/mapping of full catalog collections during Home empty-state checks, and backs off hero timer work while the hero carousel is paused or scrolled below the fold.

Root Cause

1. Derived content emptiness checks: HomeView.isEmpty referenced recentlyWatched.isEmpty and favorites.isEmpty. Evaluating each computed property mapped and sorted the full set of watched/favorite movies, series, and channels across the active playlist just to check for presence.
2. Paused TV hero auto-advance wakeups: runAutoAdvance() in TVHomeScreen ticked every 50 ms (20 Hz) regardless of whether the hero was below the fold (isPaused), and unconditionally assigned progress = 0 on every tick, causing continuous @Observable writes and main thread churn when browsing lower rails.

Changes

1. Presence & Emptiness Optimization (HomeDerivedContent.swift):
   • Added HomeDerivedContent.hasRecentlyWatched(...) and HomeDerivedContent.hasFavorites(...) that early-exit on the first matching item with O(1) scans.
   • Guarded row evaluation in homeRow(for:) (hasRecentlyWatched ? recentlyWatched : [] and hasFavorites ? favorites : []), skipping full array generation when rails are empty.
   • Refactored recentlyWatched and favorites generation into HomeDerivedContent to keep HomeView.swift within size limits.
2. Hero Auto-Advance Backoff (TVHomeScreen.swift):
   • Guarded progress = 0 writes in TVHeroModel to only execute when progress != 0, preventing redundant notifications.
   • In runAutoAdvance(), increased sleep duration to 200 ms while model.isPaused, reducing idle wakeups by 75% when scrolled below the fold.
   • Added .onDisappear { model.isPaused = true } and .onAppear { model.isPaused = zone != .expanded }.
   • Exposed TVHeroModel in #if os(tvOS) || DEBUG so it can be verified via unit tests on simulator hosts.
3. Tests (HomeIdleWorkTests.swift):
   • Unit tests covering presence check equivalence to full rail arrays.
   • Coverage for parental restrictions, playlist scoping, and live TV inclusion switches.
   • Unit tests for TVHeroModel progress ticking, auto-advance, dwell preservation, and paused state behavior.

Validation

• HomeIdleWorkTests: 8 / 8 tests passed.
• Regression suite (HomeLayoutSettingsTests, HomeDownloadsTests, MediaFavoritesTests): 30 / 30 tests passed.
• Scripts/lint-tool.sh swiftformat and swiftlint: 0 warnings, 0 violations.