v3: code quality pass

src/pages/UserLogin.tsx

@@ -3,7 +3,12 @@ import type { SubmitEvent } from "react";
 import { useNavigate } from "react-router";
 
 import { API_URL } from "../config/api.ts";
-import { deserializeAuthResponse } from "../model.ts";
+import {
+  deserializeAuthResponse,
+  type LoginRequest,
+  parseAPIResponse,
+  type RawAuthResponse,
+} from "../model.ts";
 import { useAuth } from "../hooks/useAuth.ts";
 import { PageShell } from "../components/PageShell.tsx";
 import { ErrorCard } from "../components/ErrorCard.tsx";
@@ -26,26 +31,23 @@ export function UserLogin() {
     setState({ status: "submitting" });
 
     const formData = new FormData(e.currentTarget);
-    const username = formData.get("username");
-    const password = formData.get("password");
+    const username = formData.get("username") as string;
+    const password = formData.get("password") as string;
 
     try {
       const res = await fetch(`${API_URL}/api/users/login`, {
         method: "POST",
         headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ username, password }),
+        body: JSON.stringify({ username, password } satisfies LoginRequest),
       });
 
-      const apiResponse = await res.json();
+      const apiResponse = parseAPIResponse<RawAuthResponse>(await res.json());
 
       if (apiResponse.success) {
         login(deserializeAuthResponse(apiResponse.data));
         navigate("/");
       } else {
-        setState({
-          status: "error",
-          error: apiResponse.error?.message ?? "Login failed.",
-        });
+        setState({ status: "error", error: apiResponse.error.message });
       }
     } catch (err) {
       setState({ status: "error", error: friendlyFetchError(err) });