Global error page: ErrorView with per-status copy, did-you-mean suggestions, error ids from handleError, static error.html; 404 instead of 500 for bad progress ids; tolerate full header line in DAISY_TASK_WEBHOOK_HEADER and stop logging raw fetch errors

src/hooks.client.ts

@@ -0,0 +1,10 @@
+import type { HandleClientError } from '@sveltejs/kit';
+
+// Errors thrown while rendering/loading in the browser: same shape as the server (short id,
+// generic message) so the error page looks the same either way.
+export const handleError: HandleClientError = ({ error, status, message }) => {
+	if (status === 404) return { message: 'Not Found' };
+	const id = crypto.randomUUID().slice(0, 8);
+	console.error(`[error ${id}] ${status}`, error);
+	return { message: status >= 500 ? 'Internal Error' : message, id };
+};