fix(admin): add favicon and page-aware titles

admin/tests/views/App.test.ts

@@ -19,6 +19,7 @@ beforeEach(() => {
 
 afterEach(() => {
   document.body.innerHTML = ''
+  document.title = ''
 })
 
 enableAutoUnmount(afterEach)
@@ -28,6 +29,7 @@ describe('app root', () => {
     const { wrapper } = await mountAt('/login')
     expect(wrapper.find('nav[aria-label="Wtyczki"]').exists()).toBe(false)
     expect(wrapper.find('form').exists()).toBe(true)
+    expect(document.title).toBe('Witaj ponownie | SummerCMS')
   })
 
   it('renders shell routes inside the shell and an unknown path as not found', async () => {
@@ -37,6 +39,7 @@ describe('app root', () => {
     expect(wrapper.find('nav[aria-label="Wtyczki"]').exists()).toBe(true)
     expect(wrapper.findComponent(NotFoundView).exists()).toBe(true)
     expect(wrapper.find('main h1').text()).toBe('Nie znaleziono strony.')
+    expect(document.title).toBe('Nie znaleziono strony. | SummerCMS')
   })
 
   it('says so when the admin may open no plugin', async () => {