test: add comprehensive test coverage structure

- Add accessibility tests for ResetPasswordPage component
- Add performance tests for schedule generation
- Add visual regression tests with snapshot baselines
- Establish testing patterns for UI accessibility compliance
- Include performance benchmarks for core utilities

tests/performance/schedule.performance.test.ts

@@ -0,0 +1,26 @@
+import { generateSchedule } from '../../utils/schedule';
+import { Frequency, Medication } from '../../types';
+
+describe('Performance: schedule generation', () => {
+  const createMedication = (index: number): Medication => ({
+    _id: `med-${index}`,
+    _rev: `1-${index}`,
+    name: `Medication ${index}`,
+    dosage: '10mg',
+    frequency: Frequency.Daily,
+    startTime: '08:00',
+    icon: 'pill',
+  });
+
+  test('generates schedule for 1000 medications under 1 second', () => {
+    const medications = Array.from({ length: 1000 }, (_, idx) =>
+      createMedication(idx)
+    );
+    const start = performance.now();
+    const schedule = generateSchedule(medications, new Date());
+    const duration = performance.now() - start;
+
+    expect(schedule.length).toBe(medications.length);
+    expect(duration).toBeLessThan(1000);
+  });
+});