feat: redesign day picker with expandable calendar, status markers & Playwright E2E testing

- Replace modal calendar with inline expandable calendar widget integrated into the day picker.
- Add status indicator dots (attended/absent/pending) to month calendar grid matching day picker.
- Disable and gray out weekend days in calendar when weekend schedule is turned off.
- Redesign extend bar with integrated handle that aligns with the palette.
- Remove start-to-end timing on Today screen's class time rail, showing only start time.
- Implement Playwright E2E and visual testing suite with multi-screen capture scripts.
- Add cascade DELETE endpoints for subjects and versioned recurring timetable entries.

e2e/app.spec.ts

@@ -0,0 +1,70 @@
+import { test, expect } from '@playwright/test';
+
+test.describe('College Kit E2E & Visual Verification', () => {
+  test.beforeEach(async ({ page }) => {
+    // Ensure profile is setup so we are on the main tabs
+    await page.request.put('http://localhost:4000/api/v1/profile', {
+      data: {
+        name: 'Sam Taylor',
+        college: 'Northbridge University',
+        programme: 'B.Tech Computer Science',
+        semester: 'Semester 3',
+      },
+    });
+  });
+
+  test('Today screen loads with date, week strip, and classes', async ({ page }) => {
+    await page.goto('/');
+    await expect(page.locator('text=Today’s classes')).toBeVisible();
+    await expect(page.locator('text=Timetable')).toBeVisible();
+    await expect(page.locator('text=Attendance')).toBeVisible();
+    await expect(page.locator('text=Settings')).toBeVisible();
+  });
+
+  test('Navigation between all bottom tabs works smoothly', async ({ page }) => {
+    await page.goto('/');
+
+    // Navigate to Timetable
+    await page.locator('text=Timetable').click();
+    await expect(page.locator('text=Week of')).toBeVisible();
+
+    // Navigate to Attendance
+    await page.getByRole('button', { name: 'Attendance' }).click();
+    await expect(page.locator('text=By subject')).toBeVisible();
+    await expect(page.locator('text=Classes held')).toBeVisible();
+
+    // Navigate to Settings
+    await page.getByRole('button', { name: 'Settings' }).click();
+    await expect(page.locator('text=Shape your class day')).toBeVisible();
+    await expect(page.locator('text=Default class length')).toBeVisible();
+
+    // Navigate back to Today
+    await page.getByRole('button', { name: 'Today' }).click();
+    await expect(page.locator('text=classes').first()).toBeVisible();
+  });
+
+  test('Account screen displays profile information correctly', async ({ page }) => {
+    await page.goto('/account');
+    await expect(page.locator('text=Sam Taylor')).toBeVisible();
+    await expect(page.getByText('Northbridge University').first()).toBeVisible();
+    await expect(page.locator('text=B.Tech Computer Science')).toBeVisible();
+  });
+
+  test('Subject Details screen loads subject metrics', async ({ page }) => {
+    // Get subjects list
+    const subjectsRes = await page.request.get('http://localhost:4000/api/v1/subjects');
+    const subjects = await subjectsRes.json();
+    if (subjects.length > 0) {
+      await page.goto(`/subjects/${subjects[0].id}`);
+      await expect(page.locator('text=Subject details')).toBeVisible();
+      await expect(page.locator('text=Recent classes')).toBeVisible();
+    }
+  });
+
+  test('Settings can be updated and saved', async ({ page }) => {
+    await page.goto('/settings');
+    await expect(page.locator('text=Save settings')).toBeVisible();
+    await page.locator('text=Save settings').click();
+    await expect(page.locator('text=Settings saved')).toBeVisible();
+  });
+});