Working login logup and logout + placeholder welcome message

dbschema/migrations/00017-m1g3r5w.edgeql

@@ -0,0 +1,11 @@
+CREATE MIGRATION m1g3r5wwsplyqphor3yvb7dzp2txacgd6ed3udrpvakuoz3e2zj7ka
+    ONTO m1t2tddtq2grfxf4ldn6aj4yotvwiqclsrks6chobvs33d5mcd62mq
+{
+  DROP GLOBAL default::currentUser;
+  CREATE GLOBAL default::current_user := (std::assert_single((SELECT
+      default::User
+  FILTER
+      (.identity = GLOBAL ext::auth::ClientTokenIdentity)
+  )));
+  DROP GLOBAL default::current_user_id;
+};

dbschema/migrations/00018-m1c2b3o.edgeql

@@ -0,0 +1,5 @@
+CREATE MIGRATION m1c2b3o4bhfgldk3kebneqyv6oxfgmorrp62uv5rreu773ryed3azq
+    ONTO m1g3r5wwsplyqphor3yvb7dzp2txacgd6ed3udrpvakuoz3e2zj7ka
+{
+  ALTER GLOBAL default::current_user RENAME TO default::currentUser;
+};

dbschema/migrations/00019-m1rzoj5.edgeql

@@ -0,0 +1,9 @@
+CREATE MIGRATION m1rzoj5rvhxkec6tsew6dc6bd3ksrrmf7t3k532avozbg4722xulhq
+    ONTO m1c2b3o4bhfgldk3kebneqyv6oxfgmorrp62uv5rreu773ryed3azq
+{
+  ALTER TYPE default::Usage {
+      ALTER LINK user {
+          RESET OPTIONALITY;
+      };
+  };
+};