v1.4.2 - Chronica: readable listing, 16:9 preview & private feed auth

A marketplace listing that says what Chronica does

plugins.omarchy.org and Omarchy's bar-widget picker both clip the description to
a single line, so the old copy stopped at "Date/time label with an interactive
calendar popup, t". Both descriptions are rewritten so the point lands in the
visible ~50 characters, and a contract test now fails when a description has no
clause break inside that window.

The preview is now 1600x900 (16:9) instead of a 1000x1000 square that the
720x405 card thumbnail cropped to its middle. It shows the headline, the sync
targets, and the bar widget above the panel it opens.

Private feeds and symlinked configs

• HTTP Basic Auth for private iCalendar/CalDAV feeds (Radicale and friends):
  add username and password to the calendar entry, or embed them in the URL.
• Symlinked config paths: calendars.json and the Google token file can now
  live behind a symlink (dotfiles repos, stow) without tripping the
  O_NOFOLLOW directory checks.

Also since v1.4.0 (1.4.1)

• Full grid & Vim navigation: h/j/k/l, 0/^/$, H/L,
  {/} for years, PgUp/PgDn, Enter to create an event, r to sync,
  w to toggle the week start.
• Shortcuts cheatsheet: press ? in the calendar popup.
• Prose cleanup across the README and comments.

Full Changelog: v1.4.0...v1.4.2