feat: add sqlite database for storing sessions (#326)

* feat: add sqlite database for storing sessions

* refactor: use db instance instead of service in auth service

* fix: coderabbit suggestions

docker-compose.dev.yml

@@ -40,6 +40,7 @@ services:
       - ./cmd:/tinyauth/cmd
       - ./main.go:/tinyauth/main.go
       - /var/run/docker.sock:/var/run/docker.sock
+      - ./data:/data
     ports:
       - 3000:3000
       - 4000:4000