feat(08-01): add isActive column, migration v3, softDeleteTask and getCompletionCount

- Add isActive BoolColumn (default true) to Tasks table
- Bump schema version from 2 to 3 with addColumn migration
- Filter watchTasksInRoom to isActive=true only
- Filter getOverdueTaskCount to isActive=true only
- Add softDeleteTask(taskId) - sets isActive=false without removing data
- Add getCompletionCount(taskId) - counts TaskCompletions for a task

lib/core/database/database.g.dart

@@ -470,6 +470,21 @@ class $TasksTable extends Tasks with TableInfo<$TasksTable, Task> {
     requiredDuringInsert: false,
     clientDefault: () => DateTime.now(),
   );
+  static const VerificationMeta _isActiveMeta = const VerificationMeta(
+    'isActive',
+  );
+  @override
+  late final GeneratedColumn<bool> isActive = GeneratedColumn<bool>(
+    'is_active',
+    aliasedName,
+    false,
+    type: DriftSqlType.bool,
+    requiredDuringInsert: false,
+    defaultConstraints: GeneratedColumn.constraintIsAlways(
+      'CHECK ("is_active" IN (0, 1))',
+    ),
+    defaultValue: const Constant(true),
+  );
   @override
   List<GeneratedColumn> get $columns => [
     id,
@@ -482,6 +497,7 @@ class $TasksTable extends Tasks with TableInfo<$TasksTable, Task> {
     effortLevel,
     nextDueDate,
     createdAt,
+    isActive,
   ];
   @override
   String get aliasedName => _alias ?? actualTableName;
@@ -555,6 +571,12 @@ class $TasksTable extends Tasks with TableInfo<$TasksTable, Task> {
         createdAt.isAcceptableOrUnknown(data['created_at']!, _createdAtMeta),
       );
     }
+    if (data.containsKey('is_active')) {
+      context.handle(
+        _isActiveMeta,
+        isActive.isAcceptableOrUnknown(data['is_active']!, _isActiveMeta),
+      );
+    }
     return context;
   }
 
@@ -608,6 +630,10 @@ class $TasksTable extends Tasks with TableInfo<$TasksTable, Task> {
         DriftSqlType.dateTime,
         data['${effectivePrefix}created_at'],
       )!,
+      isActive: attachedDatabase.typeMapping.read(
+        DriftSqlType.bool,
+        data['${effectivePrefix}is_active'],
+      )!,
     );
   }
 
@@ -633,6 +659,7 @@ class Task extends DataClass implements Insertable<Task> {
   final EffortLevel effortLevel;
   final DateTime nextDueDate;
   final DateTime createdAt;
+  final bool isActive;
   const Task({
     required this.id,
     required this.roomId,
@@ -644,6 +671,7 @@ class Task extends DataClass implements Insertable<Task> {
     required this.effortLevel,
     required this.nextDueDate,
     required this.createdAt,
+    required this.isActive,
   });
   @override
   Map<String, Expression> toColumns(bool nullToAbsent) {
@@ -670,6 +698,7 @@ class Task extends DataClass implements Insertable<Task> {
     }
     map['next_due_date'] = Variable<DateTime>(nextDueDate);
     map['created_at'] = Variable<DateTime>(createdAt);
+    map['is_active'] = Variable<bool>(isActive);
     return map;
   }
 
@@ -689,6 +718,7 @@ class Task extends DataClass implements Insertable<Task> {
       effortLevel: Value(effortLevel),
       nextDueDate: Value(nextDueDate),
       createdAt: Value(createdAt),
+      isActive: Value(isActive),
     );
   }
 
@@ -712,6 +742,7 @@ class Task extends DataClass implements Insertable<Task> {
       ),
       nextDueDate: serializer.fromJson<DateTime>(json['nextDueDate']),
       createdAt: serializer.fromJson<DateTime>(json['createdAt']),
+      isActive: serializer.fromJson<bool>(json['isActive']),
     );
   }
   @override
@@ -732,6 +763,7 @@ class Task extends DataClass implements Insertable<Task> {
       ),
       'nextDueDate': serializer.toJson<DateTime>(nextDueDate),
       'createdAt': serializer.toJson<DateTime>(createdAt),
+      'isActive': serializer.toJson<bool>(isActive),
     };
   }
 
@@ -746,6 +778,7 @@ class Task extends DataClass implements Insertable<Task> {
     EffortLevel? effortLevel,
     DateTime? nextDueDate,
     DateTime? createdAt,
+    bool? isActive,
   }) => Task(
     id: id ?? this.id,
     roomId: roomId ?? this.roomId,
@@ -757,6 +790,7 @@ class Task extends DataClass implements Insertable<Task> {
     effortLevel: effortLevel ?? this.effortLevel,
     nextDueDate: nextDueDate ?? this.nextDueDate,
     createdAt: createdAt ?? this.createdAt,
+    isActive: isActive ?? this.isActive,
   );
   Task copyWithCompanion(TasksCompanion data) {
     return Task(
@@ -780,6 +814,7 @@ class Task extends DataClass implements Insertable<Task> {
           ? data.nextDueDate.value
           : this.nextDueDate,
       createdAt: data.createdAt.present ? data.createdAt.value : this.createdAt,
+      isActive: data.isActive.present ? data.isActive.value : this.isActive,
     );
   }
 
@@ -795,7 +830,8 @@ class Task extends DataClass implements Insertable<Task> {
           ..write('anchorDay: $anchorDay, ')
           ..write('effortLevel: $effortLevel, ')
           ..write('nextDueDate: $nextDueDate, ')
-          ..write('createdAt: $createdAt')
+          ..write('createdAt: $createdAt, ')
+          ..write('isActive: $isActive')
           ..write(')'))
         .toString();
   }
@@ -812,6 +848,7 @@ class Task extends DataClass implements Insertable<Task> {
     effortLevel,
     nextDueDate,
     createdAt,
+    isActive,
   );
   @override
   bool operator ==(Object other) =>
@@ -826,7 +863,8 @@ class Task extends DataClass implements Insertable<Task> {
           other.anchorDay == this.anchorDay &&
           other.effortLevel == this.effortLevel &&
           other.nextDueDate == this.nextDueDate &&
-          other.createdAt == this.createdAt);
+          other.createdAt == this.createdAt &&
+          other.isActive == this.isActive);
 }
 
 class TasksCompanion extends UpdateCompanion<Task> {
@@ -840,6 +878,7 @@ class TasksCompanion extends UpdateCompanion<Task> {
   final Value<EffortLevel> effortLevel;
   final Value<DateTime> nextDueDate;
   final Value<DateTime> createdAt;
+  final Value<bool> isActive;
   const TasksCompanion({
     this.id = const Value.absent(),
     this.roomId = const Value.absent(),
@@ -851,6 +890,7 @@ class TasksCompanion extends UpdateCompanion<Task> {
     this.effortLevel = const Value.absent(),
     this.nextDueDate = const Value.absent(),
     this.createdAt = const Value.absent(),
+    this.isActive = const Value.absent(),
   });
   TasksCompanion.insert({
     this.id = const Value.absent(),
@@ -863,6 +903,7 @@ class TasksCompanion extends UpdateCompanion<Task> {
     required EffortLevel effortLevel,
     required DateTime nextDueDate,
     this.createdAt = const Value.absent(),
+    this.isActive = const Value.absent(),
   }) : roomId = Value(roomId),
        name = Value(name),
        intervalType = Value(intervalType),
@@ -879,6 +920,7 @@ class TasksCompanion extends UpdateCompanion<Task> {
     Expression<int>? effortLevel,
     Expression<DateTime>? nextDueDate,
     Expression<DateTime>? createdAt,
+    Expression<bool>? isActive,
   }) {
     return RawValuesInsertable({
       if (id != null) 'id': id,
@@ -891,6 +933,7 @@ class TasksCompanion extends UpdateCompanion<Task> {
       if (effortLevel != null) 'effort_level': effortLevel,
       if (nextDueDate != null) 'next_due_date': nextDueDate,
       if (createdAt != null) 'created_at': createdAt,
+      if (isActive != null) 'is_active': isActive,
     });
   }
 
@@ -905,6 +948,7 @@ class TasksCompanion extends UpdateCompanion<Task> {
     Value<EffortLevel>? effortLevel,
     Value<DateTime>? nextDueDate,
     Value<DateTime>? createdAt,
+    Value<bool>? isActive,
   }) {
     return TasksCompanion(
       id: id ?? this.id,
@@ -917,6 +961,7 @@ class TasksCompanion extends UpdateCompanion<Task> {
       effortLevel: effortLevel ?? this.effortLevel,
       nextDueDate: nextDueDate ?? this.nextDueDate,
       createdAt: createdAt ?? this.createdAt,
+      isActive: isActive ?? this.isActive,
     );
   }
 
@@ -957,6 +1002,9 @@ class TasksCompanion extends UpdateCompanion<Task> {
     if (createdAt.present) {
       map['created_at'] = Variable<DateTime>(createdAt.value);
     }
+    if (isActive.present) {
+      map['is_active'] = Variable<bool>(isActive.value);
+    }
     return map;
   }
 
@@ -972,7 +1020,8 @@ class TasksCompanion extends UpdateCompanion<Task> {
           ..write('anchorDay: $anchorDay, ')
           ..write('effortLevel: $effortLevel, ')
           ..write('nextDueDate: $nextDueDate, ')
-          ..write('createdAt: $createdAt')
+          ..write('createdAt: $createdAt, ')
+          ..write('isActive: $isActive')
           ..write(')'))
         .toString();
   }
@@ -1556,6 +1605,7 @@ typedef $$TasksTableCreateCompanionBuilder =
       required EffortLevel effortLevel,
       required DateTime nextDueDate,
       Value<DateTime> createdAt,
+      Value<bool> isActive,
     });
 typedef $$TasksTableUpdateCompanionBuilder =
     TasksCompanion Function({
@@ -1569,6 +1619,7 @@ typedef $$TasksTableUpdateCompanionBuilder =
       Value<EffortLevel> effortLevel,
       Value<DateTime> nextDueDate,
       Value<DateTime> createdAt,
+      Value<bool> isActive,
     });
 
 final class $$TasksTableReferences
@@ -1668,6 +1719,11 @@ class $$TasksTableFilterComposer extends Composer<_$AppDatabase, $TasksTable> {
     builder: (column) => ColumnFilters(column),
   );
 
+  ColumnFilters<bool> get isActive => $composableBuilder(
+    column: $table.isActive,
+    builder: (column) => ColumnFilters(column),
+  );
+
   $$RoomsTableFilterComposer get roomId {
     final $$RoomsTableFilterComposer composer = $composerBuilder(
       composer: this,
@@ -1771,6 +1827,11 @@ class $$TasksTableOrderingComposer
     builder: (column) => ColumnOrderings(column),
   );
 
+  ColumnOrderings<bool> get isActive => $composableBuilder(
+    column: $table.isActive,
+    builder: (column) => ColumnOrderings(column),
+  );
+
   $$RoomsTableOrderingComposer get roomId {
     final $$RoomsTableOrderingComposer composer = $composerBuilder(
       composer: this,
@@ -1843,6 +1904,9 @@ class $$TasksTableAnnotationComposer
   GeneratedColumn<DateTime> get createdAt =>
       $composableBuilder(column: $table.createdAt, builder: (column) => column);
 
+  GeneratedColumn<bool> get isActive =>
+      $composableBuilder(column: $table.isActive, builder: (column) => column);
+
   $$RoomsTableAnnotationComposer get roomId {
     final $$RoomsTableAnnotationComposer composer = $composerBuilder(
       composer: this,
@@ -1930,6 +1994,7 @@ class $$TasksTableTableManager
                 Value<EffortLevel> effortLevel = const Value.absent(),
                 Value<DateTime> nextDueDate = const Value.absent(),
                 Value<DateTime> createdAt = const Value.absent(),
+                Value<bool> isActive = const Value.absent(),
               }) => TasksCompanion(
                 id: id,
                 roomId: roomId,
@@ -1941,6 +2006,7 @@ class $$TasksTableTableManager
                 effortLevel: effortLevel,
                 nextDueDate: nextDueDate,
                 createdAt: createdAt,
+                isActive: isActive,
               ),
           createCompanionCallback:
               ({
@@ -1954,6 +2020,7 @@ class $$TasksTableTableManager
                 required EffortLevel effortLevel,
                 required DateTime nextDueDate,
                 Value<DateTime> createdAt = const Value.absent(),
+                Value<bool> isActive = const Value.absent(),
               }) => TasksCompanion.insert(
                 id: id,
                 roomId: roomId,
@@ -1965,6 +2032,7 @@ class $$TasksTableTableManager
                 effortLevel: effortLevel,
                 nextDueDate: nextDueDate,
                 createdAt: createdAt,
+                isActive: isActive,
               ),
           withReferenceMapper: (p0) => p0
               .map(