Web dashboard step 2: full issue pages, article chapters, POST /rate

Signed-in issue page with the Brief, downloads, index and colophon; article,
World Briefing and Behind the paper pages under the login guard; the rating
widget with its fetch enhancement; the admin-only POST /rate writing
dashboard-attributed rating events; the HMAC confirmation page links to the
site.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NHyYupFdBiR4VfoUM7NjSM

src/web/templates/world.html

@@ -0,0 +1,5 @@
+{% extends "layout.html" %}{% block content %}<article class="reading world-briefing">
+<h1>World Briefing</h1><p class="dateline">{{ display_date }}</p><hr class="rule">
+<div class="world-body">{{ body_html|safe }}</div>
+<p><a href="{{ issue_href }}">← Back to this issue</a></p>
+</article>{% endblock %}