Calendar: add events (NE Hub calendar + iCloud) and a Podcast tab

- Add, edit and delete events; month/agenda views open them on tap
- NE Hub calendar stored on the server and published as a private ICS subscribe link
- iCloud CalDAV read/write with an app-specific password (encrypted at rest,
  only *.icloud.com contacted, event addresses checked against the calendar)
- Edits patch the existing entry so alarms/attendees survive; writes use If-Match / If-None-Match
- Time zone definitions (VTIMEZONE) generated so other apps read times correctly
- Podcast tab (PODCAST_URL) alongside Podcast Admin

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

public/style.css

@@ -223,3 +223,9 @@ body.onaudio #view { flex: none; overflow: visible; padding-bottom: 8px; }
   .cday .chips em { font-style: normal; font-size: 12px; line-height: 1.25; padding: 1px 6px; border-radius: 5px; border-left: 3px solid var(--c); background: var(--panel2); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; text-align: left; }
   .cday .chips small { color: var(--muted); font-size: 11px; text-align: left; padding-left: 6px; }
 }
+
+select, textarea, input[type=date], input[type=datetime-local] { width: 100%; min-height: 48px; padding: 0 14px; border-radius: 12px; border: 1px solid var(--line); background: var(--panel); font-size: 16px; color: var(--text); }
+textarea { padding: 12px 14px; resize: vertical; font-family: inherit; }
+.chk { display: flex; align-items: center; gap: 10px; color: var(--text); font-size: 16px; margin: 14px 0 0; }
+.chk input { width: 22px; height: 22px; }
+.row input[type=checkbox] { width: 22px; height: 22px; }