Auto-login on admin page, if browser plugin is configured

Idea 1:

• Extension adds a div with api key to the admin page
• Admin page queries this div with deferred JS
• Admin page performs login with this token
• Profit

Idea 2:

• Browser addon adds Cookie (might be impossible due to HttpOnly?)

Idea 3 (wahrscheinlich am besten, quasi autofillen):

• If at /admin/login autofill password field
• Submit form