Remove dead code found by Periphery on all platforms

Delete declarations that Periphery reports unused on every platform that
compiles them (iOS, macOS, tvOS), including nine views used only by their
own previews. Platform-gated code still used on another platform, device-
only MPV render paths, migration models, CloudKit record names, App
Intents metadata and unused parameters are kept.

Yattee/Views/Search/SearchView.swift

@@ -89,10 +89,6 @@ struct SearchView: View {
         searchViewModel?.hasResults ?? false
     }
 
-    private var hasSearched: Bool {
-        searchViewModel?.hasSearched ?? false
-    }
-
     /// Initialize SearchView with optional external search text binding
     init(searchText: Binding<String>? = nil, initialQuery: String? = nil) {
         self.externalSearchText = searchText
@@ -1372,11 +1368,6 @@ struct SearchView: View {
         appEnvironment?.dataManager.deleteSearchQuery(history)
     }
 
-    private func clearAllHistory() {
-        appEnvironment?.dataManager.clearSearchHistory()
-        isSearchHistoryExpanded = false
-    }
-
     private func executeSearch(_ query: String) {
         dismissKeyboard()
         suppressNextTextChangeSearch = (query != searchTextBinding.wrappedValue)
@@ -1417,14 +1408,6 @@ struct SearchView: View {
         appEnvironment?.dataManager.deleteRecentPlaylist(playlist)
     }
 
-    private func clearAllRecentChannels() {
-        appEnvironment?.dataManager.clearRecentChannels()
-    }
-
-    private func clearAllRecentPlaylists() {
-        appEnvironment?.dataManager.clearRecentPlaylists()
-    }
-
     private func clearAllRecents() {
         appEnvironment?.dataManager.clearSearchHistory()
         appEnvironment?.dataManager.clearRecentChannels()