fix-spa-review-findings (ornith-35): fetch timeout+res.ok, AuthSection loop fix, me() timeout, enable2fa finally, TOTP mask toggle, snapshot backoff, dup key removed

Cross-review by qwopus35b pending. SPA lint 2/2 green.

app/src/lib/trpc.ts

@@ -45,22 +45,52 @@ export interface AuthUser {
   onboarded?: boolean;
 }
 
+// 8-second timeout for all tRPC calls to prevent hung requests.
+const TRPC_TIMEOUT_MS = 8_000;
+
 async function parse<T>(res: Response): Promise<T> {
+  if (!res.ok) {
+    const body = await res.text();
+    throw new Error(`tRPC ${res.status}: ${body}`);
+  }
   const json = await res.json();
   if (json?.error) {
-    const msg = json.error.message ?? `tRPC error ${json.error.data?.code ?? ""}`;
-    throw new Error(typeof msg === "string" ? msg : "tRPC error");
+    throw new Error(`tRPC error: ${json.error.message ?? json.error.data?.code ?? "unknown"}`);
   }
   return json.result.data as T;
 }
+
 async function trpcQuery<T>(procedure: string, input?: unknown): Promise<T> {
-  const search = input ? `?input=${encodeURIComponent(JSON.stringify(input))}` : "";
-  const res = await fetch(`/api/trpc/${procedure}${search}`, { headers: { "content-type": "application/json" }, credentials: "include" });
-  return parse<T>(res);
+  const controller = new AbortController();
+  const timer = setTimeout(() => controller.abort(), TRPC_TIMEOUT_MS);
+  try {
+    const search = input ? `?input=${encodeURIComponent(JSON.stringify(input))}` : "";
+    const res = await fetch(`/api/trpc/${procedure}${search}`, {
+      headers: { "content-type": "application/json" },
+      credentials: "include",
+      signal: controller.signal,
+    });
+    return parse<T>(res);
+  } finally {
+    clearTimeout(timer);
+  }
 }
+
 async function trpcMutate<T>(procedure: string, input: unknown): Promise<T> {
-  const res = await fetch(`/api/trpc/${procedure}`, { method: "POST", headers: { "content-type": "application/json" }, credentials: "include", body: JSON.stringify(input) });
-  return parse<T>(res);
+  const controller = new AbortController();
+  const timer = setTimeout(() => controller.abort(), TRPC_TIMEOUT_MS);
+  try {
+    const res = await fetch(`/api/trpc/${procedure}`, {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      credentials: "include",
+      body: JSON.stringify(input),
+      signal: controller.signal,
+    });
+    return parse<T>(res);
+  } finally {
+    clearTimeout(timer);
+  }
 }
 
 export type Complexity = "beginner" | "intermediate" | "advanced";