[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/test/domain/rules/active_habit_quota_test.dart

@@ -0,0 +1,38 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:life_helper/domain/models/habit.dart';
+import 'package:life_helper/domain/rules/active_habit_quota.dart';
+
+void main() {
+  test('build allows up to 3', () {
+    expect(
+      judgeActiveHabitQuota(type: HabitType.build, currentActiveCount: 2).allowed,
+      true,
+    );
+    expect(
+      judgeActiveHabitQuota(type: HabitType.build, currentActiveCount: 3).allowed,
+      false,
+    );
+  });
+
+  test('break allows only 1', () {
+    expect(
+      judgeActiveHabitQuota(type: HabitType.breakHabit, currentActiveCount: 0)
+          .allowed,
+      true,
+    );
+    expect(
+      judgeActiveHabitQuota(type: HabitType.breakHabit, currentActiveCount: 1)
+          .allowed,
+      false,
+    );
+  });
+
+  test('reason describes the limit when blocked', () {
+    final r = judgeActiveHabitQuota(
+        type: HabitType.build, currentActiveCount: 3);
+    expect(r.reason, contains('3'));
+    final br = judgeActiveHabitQuota(
+        type: HabitType.breakHabit, currentActiveCount: 1);
+    expect(br.reason, contains('1'));
+  });
+}