promote calendar in welcome-mail; even more robust name checking

src/model/user/mod.rs

@@ -304,16 +304,14 @@ WHERE id like ?
 
     pub async fn find_by_name(db: &SqlitePool, name: &str) -> Option<Self> {
         let name = name.trim();
-        let lowered_name = name.to_lowercase();
 
         sqlx::query_as!(
             Self,
             "
 SELECT id, name, pw, deleted, last_access, dob, weight, sex, member_since_date, birthdate, mail, nickname, phone, address, family_id, user_token
 FROM user 
-WHERE lower(name)=? OR name=?
+WHERE lower(name)=lower(?)
         ",
-            lowered_name,
             name
         )
         .fetch_one(db)