Web dashboard v2 step 4: table-of-contents sidebar

Signed-in issue pages (issue, article, world, behind) get a chapter list
that marks where the reader is. One `issue_toc` helper builds it for all
four handlers: the picks in issue order numbered across sections, then
World Briefing, Behind the paper and a colophon anchor, with
position/total over the navigable chapters.

At `lg` and up it is a sticky left column with its own sticky header
(issue number, "Chapter N of M", a 2px progress bar); below `lg` the same
`<nav>` collapses behind a sticky hamburger bar and drops down as a
panel that closes on link tap, Escape and outside tap. Without JS the
panel is simply visible; `theme.js` marks the document scripted before
paint so it never flashes open. Article pages advance the progress bar
with scroll position through `requestAnimationFrame`, and the bar is a
`<progress>` element because a percentage width would need an inline
style the CSP forbids.

Also fixes the phone "ears" row from the step 2 review: the row no
longer wraps at 390px, the dateline has a short form below `sm:`, and
the toggle and account link stay on one line.

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

src/web/templates/behind.html

@@ -1 +1,3 @@
-{% extends "layout.html" %}{% block ears %}<span>Edition notes</span>{% endblock %}{% block content %}<article class="mx-auto mt-10 max-w-[68ch] px-4 sm:mt-14 sm:px-6"><header class="mb-9"><p class="font-sans text-[0.72rem] uppercase tracking-[0.12em] text-muted">Edition notes</p><h1 class="mt-2 text-4xl font-semibold leading-[1.1] tracking-[-0.01em] sm:text-5xl">Behind the paper</h1></header><section class="border-y border-rule py-6"><p>{{ summary_line }}</p><p class="mt-3">{{ admitted_line }}</p><p class="mt-3">{{ learned_line }}</p></section><section class="mt-10"><h2 class="border-t border-rule pt-2 font-sans text-[0.72rem] font-semibold uppercase tracking-[0.12em] text-muted">Near misses</h2><p class="mt-5 italic text-ink-2">Highest utility not selected.</p>{% if near_misses.is_empty() %}<p class="mt-4 text-muted">None recorded for this run.</p>{% else %}<ol class="mt-5 list-decimal space-y-3 pl-6">{% for near_miss in near_misses %}<li>{% if page.is_admin() %}<a class="text-ink decoration-rule hover:decoration-accent" href="/dashboard/articles/{{ near_miss.article_id }}">{{ near_miss.line }}</a>{% else %}{{ near_miss.line }}{% endif %}</li>{% endfor %}</ol>{% endif %}</section><p class="mt-10 border-l-2 border-rule pl-4 italic text-ink-2">{{ models_line }}</p><p class="mt-10 border-t border-rule pt-5 font-sans text-sm"><a href="{{ issue_href }}">← Back to this issue</a></p></article>{% endblock %}
+{% extends "layout.html" %}{% block ears %}<span class="sm:hidden">{{ toc.short_date }}</span><span class="hidden sm:inline">{{ toc.display_date }} · No. {{ toc.issue_number }}</span>{% endblock %}{% block content %}<div class="mx-auto max-w-7xl lg:grid lg:grid-cols-[16rem_minmax(0,1fr)] lg:gap-x-10 lg:px-6 xl:grid-cols-[18rem_minmax(0,1fr)] xl:gap-x-14">{% include "_toc.html" %}
+<article class="mx-auto mt-10 w-full max-w-[68ch] px-4 sm:px-6 lg:mt-12 lg:px-0"><header class="mb-9"><p class="font-sans text-[0.72rem] uppercase tracking-[0.12em] text-muted">Edition notes</p><h1 class="mt-2 text-4xl font-semibold leading-[1.1] tracking-[-0.01em] sm:text-5xl">Behind the paper</h1></header><section class="border-y border-rule py-6"><p>{{ summary_line }}</p><p class="mt-3">{{ admitted_line }}</p><p class="mt-3">{{ learned_line }}</p></section><section class="mt-10"><h2 class="border-t border-rule pt-2 font-sans text-[0.72rem] font-semibold uppercase tracking-[0.12em] text-muted">Near misses</h2><p class="mt-5 italic text-ink-2">Highest utility not selected.</p>{% if near_misses.is_empty() %}<p class="mt-4 text-muted">None recorded for this run.</p>{% else %}<ol class="mt-5 list-decimal space-y-3 pl-6">{% for near_miss in near_misses %}<li>{% if page.is_admin() %}<a class="text-ink decoration-rule hover:decoration-accent" href="/dashboard/articles/{{ near_miss.article_id }}">{{ near_miss.line }}</a>{% else %}{{ near_miss.line }}{% endif %}</li>{% endfor %}</ol>{% endif %}</section><p class="mt-10 border-l-2 border-rule pl-4 italic text-ink-2">{{ models_line }}</p><p class="mt-10 border-t border-rule pt-5 font-sans text-sm"><a href="{{ issue_href }}">← Back to this issue</a></p></article>
+</div>{% endblock %}