feat(02-01): Drift tables, DAOs, scheduling utility, domain models with tests

- Add Rooms, Tasks, TaskCompletions Drift tables with schema v2 migration
- Create RoomsDao with CRUD, watchAll, watchWithStats, cascade delete, reorder
- Create TasksDao with CRUD, watchInRoom (sorted by due), completeTask, overdue detection
- Implement calculateNextDueDate and catchUpToPresent pure scheduling functions
- Define IntervalType enum (8 types), EffortLevel enum, FrequencyInterval model
- Add formatRelativeDate German formatter and curatedRoomIcons icon list
- Enable PRAGMA foreign_keys in beforeOpen migration strategy
- All 30 unit tests passing (17 scheduling + 6 rooms DAO + 7 tasks DAO)

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

lib/core/database/database.dart

@@ -2,14 +2,75 @@ import 'package:drift/drift.dart';
 import 'package:drift_flutter/drift_flutter.dart';
 import 'package:path_provider/path_provider.dart';
 
+import '../../features/rooms/data/rooms_dao.dart';
+import '../../features/tasks/data/tasks_dao.dart';
+import '../../features/tasks/domain/effort_level.dart';
+import '../../features/tasks/domain/frequency.dart';
+
 part 'database.g.dart';
 
-@DriftDatabase(tables: [])
+/// Rooms table: each room has a name, icon, and sort order.
+class Rooms extends Table {
+  IntColumn get id => integer().autoIncrement()();
+  TextColumn get name => text().withLength(min: 1, max: 100)();
+  TextColumn get iconName => text()();
+  IntColumn get sortOrder => integer().withDefault(const Constant(0))();
+  DateTimeColumn get createdAt =>
+      dateTime().clientDefault(() => DateTime.now())();
+}
+
+/// Tasks table: each task belongs to a room and has scheduling info.
+class Tasks extends Table {
+  IntColumn get id => integer().autoIncrement()();
+  IntColumn get roomId => integer().references(Rooms, #id)();
+  TextColumn get name => text().withLength(min: 1, max: 200)();
+  TextColumn get description => text().nullable()();
+  IntColumn get intervalType => intEnum<IntervalType>()();
+  IntColumn get intervalDays =>
+      integer().withDefault(const Constant(1))();
+  IntColumn get anchorDay => integer().nullable()();
+  IntColumn get effortLevel => intEnum<EffortLevel>()();
+  DateTimeColumn get nextDueDate => dateTime()();
+  DateTimeColumn get createdAt =>
+      dateTime().clientDefault(() => DateTime.now())();
+}
+
+/// TaskCompletions table: records when a task was completed.
+class TaskCompletions extends Table {
+  IntColumn get id => integer().autoIncrement()();
+  IntColumn get taskId => integer().references(Tasks, #id)();
+  DateTimeColumn get completedAt => dateTime()();
+}
+
+@DriftDatabase(
+  tables: [Rooms, Tasks, TaskCompletions],
+  daos: [RoomsDao, TasksDao],
+)
 class AppDatabase extends _$AppDatabase {
-  AppDatabase([QueryExecutor? executor]) : super(executor ?? _openConnection());
+  AppDatabase([QueryExecutor? executor])
+      : super(executor ?? _openConnection());
 
   @override
-  int get schemaVersion => 1;
+  int get schemaVersion => 2;
+
+  @override
+  MigrationStrategy get migration {
+    return MigrationStrategy(
+      onCreate: (Migrator m) async {
+        await m.createAll();
+      },
+      onUpgrade: (Migrator m, int from, int to) async {
+        if (from < 2) {
+          await m.createTable(rooms);
+          await m.createTable(tasks);
+          await m.createTable(taskCompletions);
+        }
+      },
+      beforeOpen: (details) async {
+        await customStatement('PRAGMA foreign_keys = ON');
+      },
+    );
+  }
 
   static QueryExecutor _openConnection() {
     return driftDatabase(

lib/core/database/database.steps.dart

@@ -0,0 +1,247 @@
+// dart format width=80
+import 'package:drift/internal/versioned_schema.dart' as i0;
+import 'package:drift/drift.dart' as i1;
+import 'package:drift/drift.dart'; // GENERATED BY drift_dev, DO NOT MODIFY.
+
+// ignore_for_file: type=lint,unused_import
+//
+final class Schema2 extends i0.VersionedSchema {
+  Schema2({required super.database}) : super(version: 2);
+  @override
+  late final List<i1.DatabaseSchemaEntity> entities = [
+    rooms,
+    tasks,
+    taskCompletions,
+  ];
+  late final Shape0 rooms = Shape0(
+    source: i0.VersionedTable(
+      entityName: 'rooms',
+      withoutRowId: false,
+      isStrict: false,
+      tableConstraints: [],
+      columns: [_column_0, _column_1, _column_2, _column_3, _column_4],
+      attachedDatabase: database,
+    ),
+    alias: null,
+  );
+  late final Shape1 tasks = Shape1(
+    source: i0.VersionedTable(
+      entityName: 'tasks',
+      withoutRowId: false,
+      isStrict: false,
+      tableConstraints: [],
+      columns: [
+        _column_0,
+        _column_5,
+        _column_1,
+        _column_6,
+        _column_7,
+        _column_8,
+        _column_9,
+        _column_10,
+        _column_11,
+        _column_4,
+      ],
+      attachedDatabase: database,
+    ),
+    alias: null,
+  );
+  late final Shape2 taskCompletions = Shape2(
+    source: i0.VersionedTable(
+      entityName: 'task_completions',
+      withoutRowId: false,
+      isStrict: false,
+      tableConstraints: [],
+      columns: [_column_0, _column_12, _column_13],
+      attachedDatabase: database,
+    ),
+    alias: null,
+  );
+}
+
+class Shape0 extends i0.VersionedTable {
+  Shape0({required super.source, required super.alias}) : super.aliased();
+  i1.GeneratedColumn<int> get id =>
+      columnsByName['id']! as i1.GeneratedColumn<int>;
+  i1.GeneratedColumn<String> get name =>
+      columnsByName['name']! as i1.GeneratedColumn<String>;
+  i1.GeneratedColumn<String> get iconName =>
+      columnsByName['icon_name']! as i1.GeneratedColumn<String>;
+  i1.GeneratedColumn<int> get sortOrder =>
+      columnsByName['sort_order']! as i1.GeneratedColumn<int>;
+  i1.GeneratedColumn<int> get createdAt =>
+      columnsByName['created_at']! as i1.GeneratedColumn<int>;
+}
+
+i1.GeneratedColumn<int> _column_0(String aliasedName) =>
+    i1.GeneratedColumn<int>(
+      'id',
+      aliasedName,
+      false,
+      hasAutoIncrement: true,
+      type: i1.DriftSqlType.int,
+      $customConstraints: 'NOT NULL PRIMARY KEY AUTOINCREMENT',
+    );
+i1.GeneratedColumn<String> _column_1(String aliasedName) =>
+    i1.GeneratedColumn<String>(
+      'name',
+      aliasedName,
+      false,
+      type: i1.DriftSqlType.string,
+      $customConstraints: 'NOT NULL',
+    );
+i1.GeneratedColumn<String> _column_2(String aliasedName) =>
+    i1.GeneratedColumn<String>(
+      'icon_name',
+      aliasedName,
+      false,
+      type: i1.DriftSqlType.string,
+      $customConstraints: 'NOT NULL',
+    );
+i1.GeneratedColumn<int> _column_3(String aliasedName) =>
+    i1.GeneratedColumn<int>(
+      'sort_order',
+      aliasedName,
+      false,
+      type: i1.DriftSqlType.int,
+      $customConstraints: 'NOT NULL DEFAULT 0',
+      defaultValue: const i1.CustomExpression('0'),
+    );
+i1.GeneratedColumn<int> _column_4(String aliasedName) =>
+    i1.GeneratedColumn<int>(
+      'created_at',
+      aliasedName,
+      false,
+      type: i1.DriftSqlType.int,
+      $customConstraints: 'NOT NULL',
+    );
+
+class Shape1 extends i0.VersionedTable {
+  Shape1({required super.source, required super.alias}) : super.aliased();
+  i1.GeneratedColumn<int> get id =>
+      columnsByName['id']! as i1.GeneratedColumn<int>;
+  i1.GeneratedColumn<int> get roomId =>
+      columnsByName['room_id']! as i1.GeneratedColumn<int>;
+  i1.GeneratedColumn<String> get name =>
+      columnsByName['name']! as i1.GeneratedColumn<String>;
+  i1.GeneratedColumn<String> get description =>
+      columnsByName['description']! as i1.GeneratedColumn<String>;
+  i1.GeneratedColumn<int> get intervalType =>
+      columnsByName['interval_type']! as i1.GeneratedColumn<int>;
+  i1.GeneratedColumn<int> get intervalDays =>
+      columnsByName['interval_days']! as i1.GeneratedColumn<int>;
+  i1.GeneratedColumn<int> get anchorDay =>
+      columnsByName['anchor_day']! as i1.GeneratedColumn<int>;
+  i1.GeneratedColumn<int> get effortLevel =>
+      columnsByName['effort_level']! as i1.GeneratedColumn<int>;
+  i1.GeneratedColumn<int> get nextDueDate =>
+      columnsByName['next_due_date']! as i1.GeneratedColumn<int>;
+  i1.GeneratedColumn<int> get createdAt =>
+      columnsByName['created_at']! as i1.GeneratedColumn<int>;
+}
+
+i1.GeneratedColumn<int> _column_5(String aliasedName) =>
+    i1.GeneratedColumn<int>(
+      'room_id',
+      aliasedName,
+      false,
+      type: i1.DriftSqlType.int,
+      $customConstraints: 'NOT NULL REFERENCES rooms(id)',
+    );
+i1.GeneratedColumn<String> _column_6(String aliasedName) =>
+    i1.GeneratedColumn<String>(
+      'description',
+      aliasedName,
+      true,
+      type: i1.DriftSqlType.string,
+      $customConstraints: 'NULL',
+    );
+i1.GeneratedColumn<int> _column_7(String aliasedName) =>
+    i1.GeneratedColumn<int>(
+      'interval_type',
+      aliasedName,
+      false,
+      type: i1.DriftSqlType.int,
+      $customConstraints: 'NOT NULL',
+    );
+i1.GeneratedColumn<int> _column_8(String aliasedName) =>
+    i1.GeneratedColumn<int>(
+      'interval_days',
+      aliasedName,
+      false,
+      type: i1.DriftSqlType.int,
+      $customConstraints: 'NOT NULL DEFAULT 1',
+      defaultValue: const i1.CustomExpression('1'),
+    );
+i1.GeneratedColumn<int> _column_9(String aliasedName) =>
+    i1.GeneratedColumn<int>(
+      'anchor_day',
+      aliasedName,
+      true,
+      type: i1.DriftSqlType.int,
+      $customConstraints: 'NULL',
+    );
+i1.GeneratedColumn<int> _column_10(String aliasedName) =>
+    i1.GeneratedColumn<int>(
+      'effort_level',
+      aliasedName,
+      false,
+      type: i1.DriftSqlType.int,
+      $customConstraints: 'NOT NULL',
+    );
+i1.GeneratedColumn<int> _column_11(String aliasedName) =>
+    i1.GeneratedColumn<int>(
+      'next_due_date',
+      aliasedName,
+      false,
+      type: i1.DriftSqlType.int,
+      $customConstraints: 'NOT NULL',
+    );
+
+class Shape2 extends i0.VersionedTable {
+  Shape2({required super.source, required super.alias}) : super.aliased();
+  i1.GeneratedColumn<int> get id =>
+      columnsByName['id']! as i1.GeneratedColumn<int>;
+  i1.GeneratedColumn<int> get taskId =>
+      columnsByName['task_id']! as i1.GeneratedColumn<int>;
+  i1.GeneratedColumn<int> get completedAt =>
+      columnsByName['completed_at']! as i1.GeneratedColumn<int>;
+}
+
+i1.GeneratedColumn<int> _column_12(String aliasedName) =>
+    i1.GeneratedColumn<int>(
+      'task_id',
+      aliasedName,
+      false,
+      type: i1.DriftSqlType.int,
+      $customConstraints: 'NOT NULL REFERENCES tasks(id)',
+    );
+i1.GeneratedColumn<int> _column_13(String aliasedName) =>
+    i1.GeneratedColumn<int>(
+      'completed_at',
+      aliasedName,
+      false,
+      type: i1.DriftSqlType.int,
+      $customConstraints: 'NOT NULL',
+    );
+i0.MigrationStepWithVersion migrationSteps({
+  required Future<void> Function(i1.Migrator m, Schema2 schema) from1To2,
+}) {
+  return (currentVersion, database) async {
+    switch (currentVersion) {
+      case 1:
+        final schema = Schema2(database: database);
+        final migrator = i1.Migrator(database, schema);
+        await from1To2(migrator, schema);
+        return 2;
+      default:
+        throw ArgumentError.value('Unknown migration from $currentVersion');
+    }
+  };
+}
+
+i1.OnUpgrade stepByStep({
+  required Future<void> Function(i1.Migrator m, Schema2 schema) from1To2,
+}) => i0.VersionedSchema.stepByStepHelper(
+  step: migrationSteps(from1To2: from1To2),
+);