feat(apple): add a Free up space action to reclaim leaked storage

Delete all transfers only clears core records, and the blob-store cache is
reclaimed by the core's own timer. Neither touches the app's temporary directory
(leftover picker/staging copies — hundreds of MB on macOS) or the stray .Trash
folders that accumulate in app-owned directories and can't be removed via
Files/Finder. Add a non-destructive Free up space button that empties the temp
directory and removes .Trash folders under the core data dir (and, on iOS, the
fixed Documents receive folder), reporting the bytes reclaimed. Guarded against
running while a transfer is in flight; never touches received files, the core
database, or user-chosen macOS receive folders.

apple/VniDrop/Features/Settings/SettingsModel.swift

@@ -56,6 +56,7 @@ struct SettingsState: Equatable {
 	var storage: StorageBreakdown?
 	var isCalculatingStorage = false
 	var isDeletingTransfers = false
+	var isCleaningStorage = false
 
 	static func == (lhs: SettingsState, rhs: SettingsState) -> Bool {
 		lhs.selectedSection == rhs.selectedSection && lhs.username == rhs.username
@@ -72,6 +73,7 @@ struct SettingsState: Equatable {
 			&& lhs.bugLogPreviewBytes == rhs.bugLogPreviewBytes
 			&& lhs.storage == rhs.storage && lhs.isCalculatingStorage == rhs.isCalculatingStorage
 			&& lhs.isDeletingTransfers == rhs.isDeletingTransfers
+			&& lhs.isCleaningStorage == rhs.isCleaningStorage
 			&& lhs.deviceInfo?.operatingSystem == rhs.deviceInfo?.operatingSystem
 	}
 }
@@ -315,6 +317,83 @@ final class SettingsModel: ObservableObject {
 		}
 	}
 
+	/// Reclaims disk space the core's transfer deletion doesn't touch: the app's
+	/// temporary directory (leftover picker/staging copies) and any stray `.Trash`
+	/// folders that accumulate inside app-owned directories. Never touches received
+	/// files, the core database, or user-chosen receive folders.
+	func freeUpSpace() {
+		if state.isCleaningStorage { return }
+		// Purging staging while a transfer is mid-flight could break it.
+		let hasActive = repository.state.transfers.contains {
+			$0.status == .sharing || $0.status == .importing || $0.status == .receiving
+		}
+		if hasActive {
+			messages.tryShow(UiMessage(text: .resource(L10n.Storage.cleanupBusy), tone: .warning))
+			return
+		}
+		state.isCleaningStorage = true
+		let tempDir = NSTemporaryDirectory()
+		let dataDir = environment.defaultCoreDataDir
+		// Only clean the receive folder's trash when it is app-owned (iOS fixed
+		// Documents), never a user-chosen macOS folder like ~/Downloads.
+		let receiveTrashRoot = fileSystemService.supportsCustomReceiveFolders ? nil : state.receiveFolder?.value
+		Task {
+			let freed = await Task.detached {
+				SettingsModel.reclaimJunk(tempDir: tempDir, dataDir: dataDir, receiveTrashRoot: receiveTrashRoot)
+			}.value
+			state.isCleaningStorage = false
+			loadStorageUsage()
+			messages.show(UiMessage(
+				text: .dynamic(L10n.Storage.cleanupFreed(size: formatBytes(freed))),
+				tone: .success
+			))
+		}
+	}
+
+	/// Deletes temp-directory contents and `.Trash` folders under the given roots,
+	/// returning the number of bytes reclaimed. Runs off the main actor.
+	nonisolated static func reclaimJunk(tempDir: String, dataDir: String, receiveTrashRoot: String?) -> UInt64 {
+		let fm = FileManager.default
+		var freed: UInt64 = 0
+		// Empty the temporary directory.
+		if let entries = try? fm.contentsOfDirectory(atPath: tempDir) {
+			for name in entries {
+				let path = (tempDir as NSString).appendingPathComponent(name)
+				freed += itemSize(path)
+				try? fm.removeItem(atPath: path)
+			}
+		}
+		// Remove stray `.Trash` folders inside app-owned directories.
+		for root in [dataDir, receiveTrashRoot].compactMap({ $0 }) {
+			for trash in trashDirectories(under: root) {
+				freed += directorySize(trash)
+				try? fm.removeItem(atPath: trash)
+			}
+		}
+		return freed
+	}
+
+	/// Paths of every directory named `.Trash` under `root` (not descending into them).
+	private nonisolated static func trashDirectories(under root: String) -> [String] {
+		let url = URL(fileURLWithPath: root, isDirectory: true)
+		guard let enumerator = FileManager.default.enumerator(
+			at: url, includingPropertiesForKeys: [.isDirectoryKey]
+		) else { return [] }
+		var result: [String] = []
+		for case let fileURL as URL in enumerator where fileURL.lastPathComponent == ".Trash" {
+			result.append(fileURL.path)
+			enumerator.skipDescendants()
+		}
+		return result
+	}
+
+	/// Allocated size of a file or directory (0 if missing).
+	private nonisolated static func itemSize(_ path: String) -> UInt64 {
+		var isDirectory: ObjCBool = false
+		guard FileManager.default.fileExists(atPath: path, isDirectory: &isDirectory) else { return 0 }
+		return isDirectory.boolValue ? directorySize(path) : fileSize(path)
+	}
+
 	nonisolated static func fileSize(_ path: String) -> UInt64 {
 		let values = try? URL(fileURLWithPath: path).resourceValues(
 			forKeys: [.isRegularFileKey, .totalFileAllocatedSizeKey, .fileSizeKey]

apple/VniDrop/Features/Settings/SettingsSections.swift

@@ -99,6 +99,23 @@ struct StorageSettings: View {
 			Text(String(localized: L10n.Storage.footer))
 		}
 
+		Section {
+			Button {
+				model.freeUpSpace()
+			} label: {
+				HStack {
+					Text(model.state.isCleaningStorage
+						 ? String(localized: L10n.Storage.cleaning)
+						 : String(localized: L10n.Storage.freeUpSpace))
+					if model.state.isCleaningStorage {
+						Spacer()
+						ProgressView()
+					}
+				}
+			}
+			.disabled(model.state.isCleaningStorage)
+		}
+
 		Section {
 			Button(role: .destructive) {
 				showDeleteConfirmation = true