make 'Vorgangsname' column unique

src/init/init_db.js

@@ -30,7 +30,7 @@ for (const usr of stmt.iterate()) {
 create_stmt = `CREATE TABLE IF NOT EXISTS cases
         (id INTEGER PRIMARY KEY AUTOINCREMENT,
         token TEXT NOT NULL UNIQUE,
-        name TEXT NOT NULL,
+        name TEXT NOT NULL UNIQUE,
         pw TEXT NOT NULL)`;
 
 db.exec(create_stmt);