iCloud: recognise Apple's calendar entries; say what was seen when none match

Apple writes <calendar xmlns="urn:ietf:params:xml:ns:caldav"/> (attributes, no prefix), which the
previous pattern missed, so a valid sign-in reported "No calendars found". Match it with a
lookahead, check the HTTP status of the listing, and name what iCloud returned if nothing matches.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

caldav.js

@@ -65,10 +65,15 @@ async function connect(appleId, password) {
   if (!homeHref) throw new Error('Could not find the calendar home for this account');
   const home = abs(homeHref, b.url);
   const c = await dav('PROPFIND', home, { ...o, depth: 1, body: PROPFIND_CALS });
-  const calendars = [];
+  if (c.status >= 400) throw new Error(`iCloud answered ${c.status} when listing the calendars`);
+  const calendars = [], seen = [];
   for (const r of responses(c.text)) {
     const rt = tag(r, 'resourcetype') || '';
-    if (!/<(?:\w+:)?calendar\s*\/?>/i.test(rt)) continue;
+    // Apple writes <calendar xmlns="urn:ietf:params:xml:ns:caldav"/> (with attributes, and often no prefix); the lookahead keeps
+    // calendar-proxy-read, calendar-home-set etc. from matching.
+    const isCal = /<(?:[\w-]+:)?calendar(?=[\s/>])/i.test(rt);
+    seen.push(isCal ? 'calendar' : (rt.replace(/<(?:[\w-]+:)?([\w-]+)[^>]*>/g, '$1 ').trim() || 'other').slice(0, 30));
+    if (!isCal) continue;
     const comps = tag(r, 'supported-calendar-component-set');
     const events = !comps || /name="VEVENT"/i.test(comps), todos = !!comps && /name="VTODO"/i.test(comps);
     if (!events && !todos) continue;
@@ -76,7 +81,7 @@ async function connect(appleId, password) {
     const color = (tag(r, 'calendar-color') || '').trim().slice(0, 7);
     calendars.push({ id: calId(href), href, name: decode(tag(r, 'displayname') || 'Calendar').trim() || 'Calendar', color: /^#[0-9a-f]{6}$/i.test(color) ? color : '#d9453a', enabled: true, events, todos });
   }
-  if (!calendars.length) throw new Error('No calendars found on this account');
+  if (!calendars.length) throw new Error(`Signed in, but no calendars were found (iCloud listed ${seen.length} item${seen.length === 1 ? '' : 's'}: ${seen.slice(0, 6).join(', ') || 'none'}). Make sure Calendar is turned on for this Apple ID in iCloud settings.`);
   save({ user: o.user, pass: o.pass, calendars });
   return status();
 }