feat: import work hours from SaaS and exchange signed time sheet

.env

@@ -97,6 +97,12 @@ APPLICATION_FORM_API_KEY=
 # an invitation with a dead booking link is worse than none.
 APPLICATION_FORM_BOOKING_URL=
 
+# SaaS time tracking. Season teamers clock their hours here; app:saas:work-hours imports them.
+# The API key travels in the URL path, so it never belongs in the committed file - set both
+# values in .env.local / the server environment.
+APP_SAAS_BASE_URL=
+APP_SAAS_API_KEY=
+
 ###> symfony/mailjet-mailer ###
 # Bulk teamer mailings only, everything else goes out over MAILER_DSN. Set the real
 # credentials in .env.local - the sending domain has to be verified in Mailjet (SPF,