OAuth2 OpenID Connect provider support, API and DB refactoring (#3)

Allows Paskia to authenticate the user to a client site.
- User friendly client registration flow on the admin app
- Redirect-based authentication flow (per spec)
- Backchannel logout both ways to keep sessions synchronized
- Groups integrated with Paskia's permission system
- Adds email, preferred username and telephone fields on user profile
- All new user basic info layout to show the new information, better looks
- API and DB structures redesigned
- Various unrelated fixes to theming and layout

e2e/playwright.config.js

@@ -4,7 +4,7 @@ import { defineConfig, devices } from '@playwright/test'
  * Playwright configuration for Paskia E2E tests.
  * Uses Chrome's Virtual Authenticator for automated passkey testing.
  *
- * Run with: bun run test
+ * Run with: npm test
  */
 
 export default defineConfig({