[Developer] #204 Phase 1 MVP — Flutter app skeleton complete

- Drift 21 tables (8 catalog + 11 user + habit_dose_variants + meta_kv)
  with R1~R10 CHECK constraints and 19 indexes
- 8 hand-crafted seed JSON catalogs in app/assets/seed/
  (refs 84, protocols 34, methodologies 21, frame_patterns 30,
   reward_menu_items 30, break_protocols 8, common_frames 5, diet_patterns 5)
- 6 domain functions: recommend_variant, compute_streak,
  validate_frame_level, active_habit_quota, weekly_minimum_ratio,
  seed_importer (transactional, idempotent)
- 4 vertical-slice Riverpod screens: HabitList, HabitCreate, CheckIn, Streak
- 31 unit tests passing; flutter analyze clean
- OQ-5 streak semantics: missing entry ≠ explicit blank
  (missing = end of history; only TrackerValue.blank triggers Never-miss-twice)

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

app/lib/data/db/daos/tracker_dao.dart

@@ -0,0 +1,80 @@
+import 'package:drift/drift.dart';
+
+import '../../../core/id.dart';
+import '../../../core/time.dart';
+import '../app_database.dart';
+import '../tables/user_tables.dart';
+
+part 'tracker_dao.g.dart';
+
+class TrackerEntryDraft {
+  final String habitId;
+  final String date; // YYYY-MM-DD
+  final String value; // done | blank
+  final String? variantId;
+  final String? ctxLocation;
+  final String? ctxCondition;
+  final String? note;
+
+  const TrackerEntryDraft({
+    required this.habitId,
+    required this.date,
+    required this.value,
+    this.variantId,
+    this.ctxLocation,
+    this.ctxCondition,
+    this.note,
+  });
+}
+
+@DriftAccessor(tables: [TrackerEntries])
+class TrackerDao extends DatabaseAccessor<AppDatabase> with _$TrackerDaoMixin {
+  TrackerDao(super.db);
+
+  Future<String> recordCheckIn(TrackerEntryDraft draft) async {
+    final id = generateUlid('te');
+    await into(trackerEntries).insert(TrackerEntriesCompanion.insert(
+      id: id,
+      habitId: draft.habitId,
+      date: draft.date,
+      value: draft.value,
+      loggedAt: Value(nowKst().toIso8601String()),
+      variantId: Value(draft.variantId),
+      ctxLocation: Value(draft.ctxLocation),
+      ctxCondition: Value(draft.ctxCondition),
+      note: Value(draft.note),
+    ));
+    return id;
+  }
+
+  Future<List<TrackerEntry>> entriesForHabit(String habitId) {
+    return (select(trackerEntries)
+          ..where((t) => t.habitId.equals(habitId))
+          ..orderBy([(t) => OrderingTerm.asc(t.date)]))
+        .get();
+  }
+
+  /// Done entries in [start, end) for one user.
+  /// [start]/[end] are YYYY-MM-DD strings.
+  Future<List<TrackerEntry>> findDoneInRangeForUser({
+    required String userId,
+    required String startDate,
+    required String endDate,
+    String? habitId,
+  }) async {
+    final habitIds = await (select(db.habits)
+          ..where((t) => t.userId.equals(userId)))
+        .map((h) => h.id)
+        .get();
+    if (habitIds.isEmpty) return const [];
+    final query = select(trackerEntries)
+      ..where((t) => t.habitId.isIn(habitIds))
+      ..where((t) => t.value.equals('done'))
+      ..where((t) =>
+          t.date.isBiggerOrEqualValue(startDate) & t.date.isSmallerThanValue(endDate));
+    if (habitId != null) {
+      query.where((t) => t.habitId.equals(habitId));
+    }
+    return query.get();
+  }
+}