refactor: replace signIn callback with signIn event, adjust getUserByEmail in adapter to check provider (#1223)

* refactor: replace signIn callback with signIn event, adjust getUserByEmail in adapter to check provider

* test: adjusting tests for adapter and events

* docs: add comments for unknown auth provider

* fix: missing dayjs import

packages/auth/session.ts

@@ -5,7 +5,8 @@ import type { Database } from "@homarr/db";
 
 import { getCurrentUserPermissionsAsync } from "./callbacks";
 
-export const sessionTokenCookieName = "next-auth.session-token";
+// Default of authjs
+export const sessionTokenCookieName = "authjs.session-token";
 
 export const expireDateAfter = (seconds: number) => {
   return new Date(Date.now() + seconds * 1000);