fix: Resolve remaining TypeScript errors

Signed-off-by: Hermes Agent <hermes@nosuchhost>

client/package-lock.json

@@ -18,6 +18,7 @@
       },
       "devDependencies": {
         "@eslint/js": "^9.10.0",
+        "@types/node": "^25.9.3",
         "@types/react": "^18.3.9",
         "@types/react-dom": "^18.3.1",
         "@vitejs/plugin-react": "^4.3.1",
@@ -1378,6 +1379,16 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/@types/node": {
+      "version": "25.9.3",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-25.9.3.tgz",
+      "integrity": "sha512-603BddQMv3pUcr4U2dhujk83N2tTDVr/34wII2B6bJy6g+8WD6yUb11jszNs0gdi4PesVWl7ABt8nYMVpnLUcg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": ">=7.24.0 <7.24.7"
+      }
+    },
     "node_modules/@types/prop-types": {
       "version": "15.7.15",
       "resolved": "https://registry.npmjs.org/@types/prop-types/-/prop-types-15.7.15.tgz",
@@ -3462,6 +3473,13 @@
         "typescript": ">=4.8.4 <6.1.0"
       }
     },
+    "node_modules/undici-types": {
+      "version": "7.24.6",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.24.6.tgz",
+      "integrity": "sha512-WRNW+sJgj5OBN4/0JpHFqtqzhpbnV0GuB+OozA9gCL7a993SmU+1JBZCzLNxYsbMfIeDL+lTsphD5jN5N+n0zg==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/update-browserslist-db": {
       "version": "1.2.3",
       "resolved": "https://registry.npmjs.org/update-browserslist-db/-/update-browserslist-db-1.2.3.tgz",