refactor: replace gorm with vanilla sql and sqlc (#541)

* refactor: replace gorm with vanilla sql and sqlc

* chore: go mod tidy

* refactor: rebase for main

* tests: fix tests

* fix: review comments

internal/model/session_model.go

@@ -1,14 +0,0 @@
-package model
-
-type Session struct {
-	UUID        string `gorm:"column:uuid;primaryKey"`
-	Username    string `gorm:"column:username"`
-	Email       string `gorm:"column:email"`
-	Name        string `gorm:"column:name"`
-	Provider    string `gorm:"column:provider"`
-	TOTPPending bool   `gorm:"column:totp_pending"`
-	OAuthGroups string `gorm:"column:oauth_groups"`
-	Expiry      int64  `gorm:"column:expiry"`
-	OAuthName   string `gorm:"column:oauth_name"`
-	OAuthSub    string `gorm:"column:oauth_sub"`
-}