Radio starts empty and fills from the Store (Add to Radio, including The Journey FM); iCloud connect falls back to the calendar home beside the principal

- Store > Radio is the station finder with Add to Radio / Added; Radio under Listen lists only what was added
- Fix the Radio tab going blank (the router passed its arguments as the Store host)
- iCloud: when the account reports no calendar home, try /<id>/calendars/, and say what iCloud answered if that fails

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

tools/caldav-test.js

@@ -0,0 +1,13 @@
+// iCloud connect: when the account does not report its calendar home at the principal, the home beside it (/<id>/calendars/) is tried.
+const http = require('http'), fs = require('fs'), os = require('os'), path = require('path');
+process.env.DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), 'cd-')); process.env.CALDAV_TEST = '1';
+const root = path.join(__dirname, '..');
+const srv = http.createServer((rq, rs) => { const p = new URL(rq.url, 'http://x').pathname, x = b => { rs.writeHead(207, { 'content-type': 'application/xml' }); rs.end('<multistatus xmlns="DAV:">' + b + '</multistatus>'); };
+  if (p === '/') return x('<response><href>/</href><propstat><prop><current-user-principal><href>/9/principal/</href></current-user-principal></prop><status>HTTP/1.1 200 OK</status></propstat></response>');
+  if (p === '/9/principal/') return x('<response><href>/9/principal/</href><propstat><prop><calendar-home-set/></prop><status>HTTP/1.1 404 Not Found</status></propstat></response>');
+  if (p === '/9/calendars/') return x('<response><href>/9/calendars/home/</href><propstat><prop><displayname>Home</displayname><resourcetype><collection/><calendar xmlns="urn:ietf:params:xml:ns:caldav"/></resourcetype></prop><status>HTTP/1.1 200 OK</status></propstat></response>');
+  rs.writeHead(404); rs.end(); }).listen(0, async () => {
+  process.env.CALDAV_BASE = 'http://127.0.0.1:' + srv.address().port;
+  const users = require(root + '/users'), caldav = require(root + '/caldav'), me = users.create({ name: 'A', role: 'admin', handle: 'YQ' });
+  await users.runAs(me, async () => { try { const s = await caldav.connect('a@icloud.com', 'abcd-efgh'); require('assert').deepEqual(s.calendars.map(c => c.name), ['Home']); console.log('caldav fallback ok'); } catch (e) { console.error(e); process.exitCode = 1; } });
+  srv.close(); process.exit(process.exitCode || 0); });