ci: remove npm audit fix from install steps

npm audit fix exits non-zero when vulnerabilities require breaking-change
upgrades (esbuild/vite, vite-plugin-pwa), blocking CI with no actionable fix.

.github/workflows/test.yml

@@ -26,7 +26,7 @@ jobs:
           cache-dependency-path: server/package-lock.json
 
       - name: Install dependencies
-        run: cd server && npm ci && npm audit fix
+        run: cd server && npm ci
 
       - name: Run tests
         run: cd server && npm run test:coverage
@@ -53,7 +53,7 @@ jobs:
           cache-dependency-path: client/package-lock.json
 
       - name: Install dependencies
-        run: cd client && npm i && npm audit fix
+        run: cd client && npm ci
 
       - name: Run tests
         run: cd client && npm run test:coverage