**Add Vitest support and migrate frontend tests**

- Added Vitest configuration (`vitest.config.mjs`) for frontend unit testing with a `jsdom` environment.
- Migrated and rewrote key frontend tests (`api.test.js`, `comiclist.test.js`, `comicreader.test.js`, `historytable.test.js`, `router.test.js`, `store.test.js`) to Vitest, improving maintainability.
- Removed `tsconfig.json` and related TypeScript loaders from `webpack` configurations (`webpack.dev.js`, `webpack.prod.js`).
- Adjusted `eslint.config.mjs` to support Vitest tests.
- Updated `package-lock.json` to include Vitest, test utilities (`jsdom`, `@vue/test-utils`), and other associated packages.
- Updated Nginx configuration for better compression on assets (`gzip` adjustments).
- Enhanced `entrypoint.sh` to include first-run library indexing (`--if-empty` argument).
- Simplified the `scan_comics` command with a dedicated test for empty database scans.

This transition improves testing workflows and backend/frontend synergy while removing unused TypeScript dependencies.

frontend/test/router.test.js

@@ -0,0 +1,50 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+vi.mock('@/api', () => ({ default: { get: vi.fn(), post: vi.fn() } }))
+
+import store from '@/store'
+import router from '@/router'
+
+beforeEach(() => {
+  localStorage.clear()
+  store.commit('logOut')
+})
+
+describe('navigation guards', () => {
+  it('redirects an anonymous user to the login page', async () => {
+    await router.push('/account')
+
+    expect(router.currentRoute.value.name).toBe('login')
+    expect(router.currentRoute.value.query.error).toBe('Please log in to access this page')
+  })
+
+  it('keeps the requested path so the user returns there after logging in', async () => {
+    await router.push('/history')
+
+    expect(router.currentRoute.value.query.next).toBe('/history')
+  })
+
+  it('allows an authenticated non-admin to reach the history page', async () => {
+    store.commit('updateUser', { id: 1, is_superuser: false })
+
+    await router.push('/history')
+
+    expect(router.currentRoute.value.name).toBe('history')
+  })
+
+  it('still requires admin for the user page', async () => {
+    store.commit('updateUser', { id: 1, is_superuser: false })
+
+    await router.push('/user')
+
+    expect(router.currentRoute.value.name).toBe('login')
+  })
+
+  it('allows an admin on the user page', async () => {
+    store.commit('updateUser', { id: 1, is_superuser: true })
+
+    await router.push('/user')
+
+    expect(router.currentRoute.value.name).toBe('user')
+  })
+})