Update web installer (#614)

* update web installer

* make sure we have a user

* save SESSION_SECURE_COOKIE as text so it's written correctly to the .env

* set `SESSION_COOKIE` so session doesn't expire when changing the app name

* Allow enter to go to next step

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Co-authored-by: notCharles <charles@pelican.dev>

.env.example

@@ -4,6 +4,7 @@ APP_KEY=
 APP_TIMEZONE=UTC
 APP_URL=http://panel.test
 APP_LOCALE=en
+APP_INSTALLED=false
 
 LOG_CHANNEL=daily
 LOG_STACK=single
@@ -30,3 +31,4 @@ MAIL_FROM_NAME="Pelican Admin"
 SESSION_ENCRYPT=false
 SESSION_PATH=/
 SESSION_DOMAIN=null
+SESSION_COOKIE=pelican_session