fix: add @types/jest, fix WsAuthGuard TS error

backend/package.json

@@ -37,6 +37,7 @@
     "@nestjs/cli": "^10.0.0",
     "@nestjs/testing": "^10.0.0",
     "@types/bcrypt": "^5.0.0",
+    "@types/jest": "^30.0.0",
     "@types/node": "^20.0.0",
     "@types/passport-jwt": "^4.0.0",
     "@types/ssh2": "^1.15.0",
@@ -51,10 +52,16 @@
     "seed": "ts-node prisma/seed.ts"
   },
   "jest": {
-    "moduleFileExtensions": ["js", "json", "ts"],
+    "moduleFileExtensions": [
+      "js",
+      "json",
+      "ts"
+    ],
     "rootDir": ".",
     "testRegex": ".*\\.spec\\.ts$",
-    "transform": { "^.+\\.ts$": "ts-jest" },
+    "transform": {
+      "^.+\\.ts$": "ts-jest"
+    },
     "testEnvironment": "node",
     "moduleNameMapper": {
       "^@/(.*)$": "<rootDir>/src/$1"

backend/src/auth/ws-auth.guard.ts

@@ -11,7 +11,7 @@ export class WsAuthGuard {
       const url = new URL(client.url || client._url, 'http://localhost');
       const token = url.searchParams.get('token');
       if (!token) throw new WsException('No token');
-      return this.jwt.verify(token);
+      return this.jwt.verify(token) as { sub: number; email: string };
     } catch {
       return null;
     }