fix: return login errors to form instead of throwing (#474)

Throwing data() in React Router v7 actions goes to ErrorBoundary instead
of returning to the component. Changed validation errors to return
directly so the login form can display them properly.

app/routes/auth/login/action.ts

@@ -1,4 +1,4 @@
-import { data, redirect } from "react-router";
+import { redirect } from "react-router";
 
 import { isDataWithApiError } from "~/server/headscale/api/error-client";
 import log from "~/utils/log";
@@ -15,7 +15,10 @@ export async function loginAction({ request, context }: Route.LoaderArgs) {
       "auth",
       "If this is unexpected, ensure your reverse proxy (if applicable) is configured correctly",
     );
-    throw data("Missing `api_key`", { status: 400 });
+    return {
+      success: false,
+      message: "Missing API key. Please enter your API key.",
+    };
   }
 
   if (apiKey.length === 0) {
@@ -24,13 +27,15 @@ export async function loginAction({ request, context }: Route.LoaderArgs) {
       "auth",
       "If this is unexpected, ensure your reverse proxy (if applicable) is configured correctly",
     );
-    throw data("Received an empty `api_key`", { status: 400 });
+    return {
+      success: false,
+      message: "API key cannot be empty. Please enter a valid API key.",
+    };
   }
 
   const api = context.hsApi.getRuntimeClient(apiKey);
   try {
     const apiKeys = await api.getApiKeys();
-    console.log(apiKeys);
 
     // We don't need to check for 0 API keys because this request cannot
     // be authenticated correctly without an API key
@@ -47,7 +52,10 @@ export async function loginAction({ request, context }: Route.LoaderArgs) {
 
     if (lookup.expiration === null || lookup.expiration === undefined) {
       log.error("auth", "Got an API key without an expiration");
-      throw data("API key is malformed", { status: 500 });
+      return {
+        success: false,
+        message: "API key is malformed (missing expiration). Please generate a new API key.",
+      };
     }
 
     const expiry = new Date(lookup.expiration);