add db constraints; add optional name for login (to be sent to members)

src/tera/auth.rs

@@ -18,14 +18,18 @@ use crate::model::{
     user::{LoginError, User},
 };
 
-#[get("/")]
-fn index(flash: Option<FlashMessage<'_>>) -> Template {
+#[get("/?<name>")]
+fn index(flash: Option<FlashMessage<'_>>, name: Option<String>) -> Template {
     let mut context = tera::Context::new();
 
     if let Some(msg) = flash {
         context.insert("flash", &msg.into_inner());
     }
 
+    if let Some(n) = name {
+        context.insert("name", &n);
+    }
+
     Template::render("auth/login", context.into_json())
 }