feat(db): add memory storage driver

removes the sqlite dependency for tests, also brings back the option for
users to run zero persistence instances of tinyauth.

adds new mapErr fn for sqlc wrapper gen to prevent sql errors from
leaking out of the store implementation.

internal/bootstrap/db_bootstrap.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/tinyauthapp/tinyauth/internal/assets"
 	"github.com/tinyauthapp/tinyauth/internal/repository"
+	"github.com/tinyauthapp/tinyauth/internal/repository/memory"
 	"github.com/tinyauthapp/tinyauth/internal/repository/sqlite"
 
 	"github.com/golang-migrate/migrate/v4"
@@ -17,14 +18,14 @@ import (
 )
 
 func (app *BootstrapApp) SetupStore() (repository.Store, error) {
-	return app.setupSQLite(app.config.Database.Path)
-}
-
-// NewSQLiteStore opens a SQLite database at the given path, runs migrations, and returns a Store.
-// Useful for testing or when constructing a store outside of a BootstrapApp.
-func NewSQLiteStore(databasePath string) (repository.Store, error) {
-	app := &BootstrapApp{}
-	return app.setupSQLite(databasePath)
+	switch app.config.Database.Driver {
+	case "memory":
+		return memory.New(), nil
+	case "sqlite", "":
+		return app.setupSQLite(app.config.Database.Path)
+	default:
+		return nil, fmt.Errorf("unknown database driver %q: valid values are sqlite, memory", app.config.Database.Driver)
+	}
 }
 
 func (app *BootstrapApp) setupSQLite(databasePath string) (repository.Store, error) {