fix: json store marshaling, api handler

- code clean up
- uncomment and simplify api auth handler
- fix redirect url for frontend
- proper redirect

internal/auth/provider.go

@@ -4,4 +4,6 @@ import "net/http"
 
 type Provider interface {
 	CheckToken(r *http.Request) error
+	LoginHandler(w http.ResponseWriter, r *http.Request)
+	LogoutHandler(w http.ResponseWriter, r *http.Request)
 }