feat: basic auth shit + db init

.env.example

@@ -1 +1,13 @@
-IMAGE_PATH=
+IMAGE_PATH=/tmp
+REDIRECT_URI=http://localhost:8081/api/auth/callback
+CLIENT_ID=
+CLIENT_SECRET=
+
+# can be either postgres or sqlite
+DATABASE_TYPE=
+
+# database file, stereo.db by default.
+SQLITE_FILE=
+
+# postgres DSN, look at https://gorm.io/docs/connecting_to_the_database.html#PostgreSQL
+POSTGRES_DSN=