feat(backend): replace auth stub with real session, create users and sessions tables

backend/src/error.rs

@@ -6,8 +6,8 @@ use tracing::info;
 #[derive(Debug, Clone)]
 pub enum LoftError {
     LoginFail,
+    RegisterFail,
     AuthFailNoAuthTokenCookie,
-    AuthFailTokenWrongFormat,
     AuthFailCtxNotInRequestExt,
     FileIdNotFound,
     UndefinedErrorType,
@@ -25,8 +25,8 @@ impl IntoResponse for LoftError {
     fn into_response(self) -> axum::response::Response {
         match self {
             Self::LoginFail
+            | Self::RegisterFail
             | Self::AuthFailNoAuthTokenCookie
-            | Self::AuthFailTokenWrongFormat
             | Self::AuthFailCtxNotInRequestExt => {
                 info!("UNAUTHORIZED");
                 StatusCode::UNAUTHORIZED.into_response()