add unique name in hosting table(fix dublication error)

backend/src/db_client.py

@@ -17,7 +17,7 @@ STARTUP_TABLE_CREATION_QUERIES = {
     );""",
     "hosting": """CREATE TABLE IF NOT EXISTS hosting (
         id BIGINT AUTO_INCREMENT PRIMARY KEY,
-        Name VARCHAR(255),
+        Name VARCHAR(255) UNIQUE,
         Capacity INT,
         reservedBy VARCHAR(255)
     );""",

package-lock.json

@@ -0,0 +1,6 @@
+{
+  "name": "invitation",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {}
+}