fix(rest): 修复旧版备份恢复单次模式失效

Packages/XStatsKit/Sources/XStatsUI/State/SettingsDocument.swift

@@ -125,8 +125,9 @@ extension AppSettings {
         assign(\.restDailyGoal, option(doc.restDailyGoal, in: Self.restDailyGoalOptions))
         if let mode = doc.restMode.flatMap(RestRunMode.init(rawValue:)) {
             assign(\.restMode, mode)
-        } else {
-            assign(\.restCycleEnabled, doc.restCycleEnabled)
+        } else if let cycle = doc.restCycleEnabled {
+            // 工作番茄和单次的兼容布尔值均为 false，需比较完整模式才能正确恢复。
+            assign(\.restMode, cycle ? .cycle : .single)
         }
         assign(\.restSound, doc.restSound.flatMap(RestSound.init(rawValue:)))
         assign(\.restHUDStyle, doc.restHUDStyle.flatMap(RestHUDStyle.init(rawValue:)))

Packages/XStatsKit/Tests/XStatsUITests/RestSessionTests.swift

@@ -584,6 +584,23 @@ import Testing
         #expect(target.restHUDStyle == .hourglass)
     }
 
+    @Test(arguments: [false, true, nil] as [Bool?])
+    func legacyRestBackupRestoresModeFromWorkday(cycle: Bool?) {
+        let suite = "RestLegacyBackupTests.\(UUID())"
+        let defaults = UserDefaults(suiteName: suite)!
+        defer { defaults.removePersistentDomain(forName: suite) }
+        let settings = AppSettings(defaults: defaults)
+        settings.restMode = .workday
+        var document = SettingsDocument()
+        document.restCycleEnabled = cycle
+
+        settings.apply(document)
+
+        let expected: RestRunMode = cycle.map { $0 ? .cycle : .single } ?? .workday
+        #expect(settings.restMode == expected)
+        #expect(AppSettings(defaults: defaults).restMode == expected)
+    }
+
     @Test func workdayModeMigratesLegacyCycleAndRoundTripsBackup() {
         let oldSuite = "RestLegacyModeTests.\(UUID())"
         let oldDefaults = UserDefaults(suiteName: oldSuite)!