do not print a proxy's error page at somebody

first real test of the settings form returned openresty's 502 Bad Gateway
document, markup and all, into the panel. installing this plugin restarts
officer, and a request made inside that window reaches nginx proxy manager,
finds nothing behind it, and gets a web page back. useClient throws the
response body as the message, so the panel printed it.

worth keeping the irony: this plugin manages the proxy whose error page it
could not read.

the check is the body's SHAPE, not the status, because there is no status that
separates them — api/router.ts uses 502 for "NPM answered and refused", which
is a real answer we must not swallow. ours arrives as a sentence, theirs as a
document. gateway status AND html means the hop in front of officer answered;
html on its own still is not a sentence and says so without the tags.

all three panels go through it now.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Officer-Session: 656f5c85-e49a-4f1f-b9f3-042a04b4d043

web/ConnectionPanel.tsx

@@ -3,6 +3,7 @@ import { CheckCircle2, Loader2, Plug, ShieldAlert, Trash2, TriangleAlert } from
 import { useClient } from 'hooks/useClient';
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
+import { readableError } from './errors';
 
 /**
  * The connection to Nginx Proxy Manager — both the setup wizard and the permanent settings page.
@@ -94,9 +95,10 @@ const isForbidden = (error: unknown): boolean => (error as { status?: number })?
  * `useClient` throws `ApiError(status, message)` and nothing else — there is no `.body` to read, which is
  * the bug `HostsPanel`'s `asFailure` documents at length. The message is already the server's own text:
  * since 2026-08-25 the platform answers `{ error }` and the client unwraps it before throwing.
+ *
+ * `readableError` guards the case where that text is not Officer's at all — see `errors.ts`.
  */
-const errorText = (error: unknown): string =>
-  error instanceof Error ? error.message : 'Something went wrong.';
+const errorText = (error: unknown): string => readableError(error);
 
 export const ConnectionPanel = () => {
   const client = useClient();