Show what the pipeline understood about each article

A muted one-line note now follows every article: the deep assessment's
topic group, format, depth and technicality, the specific topics it
extracted, and the reader interests the article matched best, e.g.

  Software engineering · analysis essay · in depth · highly technical ·
  Topics: copy-on-write, ZFS · Interests: Filesystems, Rust

It renders on the web article page footer, on the public and private
issue-page entries, in the EPUB article footer and in the EPUB "In This
Issue" index (both editions), always styled like the existing meta lines
so it stays secondary to the content.

`Pick` gains `top_interests` (serde default, no migration), filled from
the signals stage when the editor assembles the lineup; the facets were
already on the issue snapshot via `Pick.llm`, so earlier issues show the
facet and topic parts and only future issues carry interests. One shared
builder, `understanding_line` in epub::chapters, feeds every surface.

The dev seed gives four picks facets and interests so the line can be
eyeballed locally.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QVPagF6jfDv78CC5Jv2wp4

src/web/issue.rs

@@ -149,6 +149,7 @@ pub async fn load(
                 why: pick_row.get("why"),
                 summary,
                 llm: None,
+                top_interests: Vec::new(),
                 discussion: None,
             });
         }
@@ -859,6 +860,7 @@ struct FullEntry {
     is_lead: bool,
     summary: String,
     why: Option<String>,
+    understanding: Option<String>,
     rating: Option<RatingWidget>,
 }
 
@@ -927,6 +929,7 @@ struct ArticleTemplate {
     meta_line: String,
     why: Option<String>,
     social_line: Option<String>,
+    understanding: Option<String>,
     summary: Option<String>,
     excerpt_only: bool,
     body_html: String,
@@ -1002,6 +1005,7 @@ pub async fn render_full(
                         .unwrap_or_default()
                         .to_string(),
                     why: pick.why.clone(),
+                    understanding: chapters::understanding_line(pick),
                     rating: is_admin.then(|| {
                         RatingWidget::for_issue(
                             pick.article.id,
@@ -1103,6 +1107,7 @@ pub async fn article(
         ),
         why: pick.why.clone(),
         social_line: chapters::social_line(&article.social),
+        understanding: chapters::understanding_line(pick),
         summary: summary_for(&view.issue, pick).map(str::to_string),
         excerpt_only: article.excerpt_only,
         body_html: prepare_body(&article.content_html),
@@ -1962,6 +1967,7 @@ mod tests {
         assert!(issue.contains("What it argues"));
         assert!(issue.contains("A short abstract for the second piece"));
         assert!(issue.contains("Why it"));
+        assert!(issue.contains("Interests: Filesystems, Rust"));
         assert!(issue.contains("World Briefing"));
         assert!(issue.contains("Behind the paper"));
         assert!(!issue.contains("Was this a good pick?"));

src/web/public.rs

@@ -54,6 +54,7 @@ pub struct PublicEntry {
     pub word_count: i64,
     pub summary: Option<String>,
     pub why: Option<String>,
+    pub understanding: Option<String>,
     pub comment_links: Vec<CommentLink>,
     pub is_lead: bool,
 }
@@ -132,6 +133,7 @@ impl From<&Issue> for PublicIssue {
                                     .filter(|summary| !summary.is_empty())
                                     .map(str::to_string),
                                 why: pick.why.clone(),
+                                understanding: crate::epub::chapters::understanding_line(pick),
                                 comment_links,
                                 is_lead: pick.is_lead,
                             }
@@ -432,13 +434,21 @@ mod tests {
     fn public_issue_shows_summaries_and_why_but_no_bodies() {
         let source = crate::epub::fixtures::issue();
         let public = PublicIssue::from(&source);
-        let html = FeedEntryTemplate { issue: &public }.render().unwrap();
+        let html = IssuePublicTemplate {
+            page: Page::new("Test issue", None, "latest"),
+            issue: public,
+            downloads: Vec::new(),
+            empty: false,
+        }
+        .render()
+        .unwrap();
         assert!(html.contains("The Lead Story"));
         assert!(html.contains("Hacker News"));
         assert!(html.contains("What it argues, and why it is worth the time."));
         assert!(html.contains("A short abstract for the second piece."));
         assert!(html.contains("The systems story with enough operational detail to matter"));
         assert!(html.contains("A small-scene delight outside the usual technical orbit"));
+        assert!(html.contains("Interests: Filesystems, Rust"));
         for private in [
             "Two stories today",
             "Body of",

src/web/templates/article.html

@@ -3,6 +3,6 @@
   <header><p class="font-sans text-[0.72rem] uppercase tracking-[0.12em] text-muted">Article</p><h1 class="mt-3 text-4xl font-semibold leading-[1.1] tracking-[-0.01em] sm:text-5xl"><a class="text-ink no-underline hover:text-accent" href="{{ source_url }}">{{ title }}</a></h1>{% match byline %}{% when Some with (byline) %}<p class="mt-5 font-sans text-sm font-medium text-ink-2">{{ byline }}</p>{% when None %}{% endmatch %}<p class="mt-1 font-sans text-sm text-muted">{{ meta_line }}</p>{% match why %}{% when Some with (why) %}<p class="mt-6 border-l-2 border-accent pl-3 italic text-ink-2">Why it's here: {{ why }}</p>{% when None %}{% endmatch %}{% match social_line %}{% when Some with (social) %}<p class="mt-4 font-sans text-sm text-muted">{{ social }}</p>{% when None %}{% endmatch %}{% match summary %}{% when Some with (summary) %}<p class="mt-7 text-xl italic leading-relaxed text-ink-2">{{ summary }}</p>{% when None %}{% endmatch %}{% if excerpt_only %}<p class="notice mt-6">Excerpt only — continue reading at the original site.</p>{% endif %}</header>
   <div class="prose-body mt-10 border-t border-rule pt-8">{{ body_html|safe }}</div>
   {% match discussion_html %}{% when Some with (discussion) %}<section class="discussion prose-body mt-12 border-t border-rule pt-6 [&_.comment-meta]:font-sans [&_.comment-meta]:text-sm [&_.comment-meta]:text-muted [&_blockquote.reply]:ml-6"><h2 class="mb-6 border-0 pt-0 text-2xl">Discussion</h2>{{ discussion|safe }}</section>{% when None %}{% endmatch %}
-  <footer class="mt-12 border-t border-rule pt-6">{% match rating %}{% when Some with (widget) %}{% include "_rating_widget.html" %}{% when None %}{% endmatch %}<p class="mt-6 flex flex-wrap gap-2"><a class="btn" href="{{ read_online_url }}">Read online ↗</a>{% if page.is_admin() %}<a class="btn" href="{{ dashboard_href }}">Dashboard</a>{% endif %}</p><nav class="mt-10 grid grid-cols-1 gap-3 font-sans sm:grid-cols-2" aria-label="Adjacent articles">{% match previous %}{% when Some with (previous) %}<a class="group min-h-24 border border-rule p-4 text-ink no-underline hover:border-accent" rel="prev" href="{{ previous.href }}"><span class="block text-[0.68rem] uppercase tracking-[0.12em] text-muted">Previous</span><span class="mt-2 block leading-snug group-hover:text-accent">← {{ previous.title }}</span></a>{% when None %}{% endmatch %}{% match next %}{% when Some with (next) %}<a class="group min-h-24 border border-rule p-4 text-right text-ink no-underline hover:border-accent sm:col-start-2" rel="next" href="{{ next.href }}"><span class="block text-[0.68rem] uppercase tracking-[0.12em] text-muted">Next</span><span class="mt-2 block leading-snug group-hover:text-accent">{{ next.title }} →</span></a>{% when None %}{% endmatch %}</nav><p class="mt-8 font-sans text-sm"><a href="{{ issue_href }}">← Back to this issue</a></p></footer>
+  <footer class="mt-12 border-t border-rule pt-6">{% match understanding %}{% when Some with (line) %}<p class="mb-6 font-sans text-sm text-muted">{{ line }}</p>{% when None %}{% endmatch %}{% match rating %}{% when Some with (widget) %}{% include "_rating_widget.html" %}{% when None %}{% endmatch %}<p class="mt-6 flex flex-wrap gap-2"><a class="btn" href="{{ read_online_url }}">Read online ↗</a>{% if page.is_admin() %}<a class="btn" href="{{ dashboard_href }}">Dashboard</a>{% endif %}</p><nav class="mt-10 grid grid-cols-1 gap-3 font-sans sm:grid-cols-2" aria-label="Adjacent articles">{% match previous %}{% when Some with (previous) %}<a class="group min-h-24 border border-rule p-4 text-ink no-underline hover:border-accent" rel="prev" href="{{ previous.href }}"><span class="block text-[0.68rem] uppercase tracking-[0.12em] text-muted">Previous</span><span class="mt-2 block leading-snug group-hover:text-accent">← {{ previous.title }}</span></a>{% when None %}{% endmatch %}{% match next %}{% when Some with (next) %}<a class="group min-h-24 border border-rule p-4 text-right text-ink no-underline hover:border-accent sm:col-start-2" rel="next" href="{{ next.href }}"><span class="block text-[0.68rem] uppercase tracking-[0.12em] text-muted">Next</span><span class="mt-2 block leading-snug group-hover:text-accent">{{ next.title }} →</span></a>{% when None %}{% endmatch %}</nav><p class="mt-8 font-sans text-sm"><a href="{{ issue_href }}">← Back to this issue</a></p></footer>
 </article>
 </div>{% endblock %}

src/web/templates/issue_full.html

@@ -5,7 +5,7 @@
   <section aria-labelledby="brief-heading" data-toc-entry="/issues/{{ date }}"><h1 id="brief-heading" class="reader-section-heading">The Brief</h1><div class="editorial prose-body mt-5 [&>p:first-child]:first-letter:float-left [&>p:first-child]:first-letter:mr-2 [&>p:first-child]:first-letter:mt-1 [&>p:first-child]:first-letter:font-serif [&>p:first-child]:first-letter:text-[4.6rem] [&>p:first-child]:first-letter:font-semibold [&>p:first-child]:first-letter:leading-[0.72]">{{ front_page_html|safe }}</div></section>
   {% if (page.is_admin() && read_href.is_some()) || downloads.is_some() %}<div class="my-8 flex flex-wrap gap-2 border-y border-rule py-4">{% if page.is_admin() %}{% match read_href %}{% when Some with (href) %}<a class="btn" href="{{ href }}" target="_blank" rel="noopener">Read in BookOrbit</a>{% when None %}{% endmatch %}{% endif %}{% match downloads %}{% when Some with (downloads) %}{% if downloads.others.is_empty() %}<a class="btn" href="{{ downloads.primary.href }}">Download {{ downloads.primary.label }}</a>{% else %}<div class="relative inline-flex"><a class="btn rounded-r-none" href="{{ downloads.primary.href }}">Download {{ downloads.primary.label }}</a><details class="-ml-px"><summary class="btn list-none rounded-l-none px-2 [&::-webkit-details-marker]:hidden" aria-label="Choose download format"><span aria-hidden="true">▾</span></summary><div class="absolute left-0 top-full z-20 mt-1 min-w-52 border border-rule bg-paper p-1 shadow-[0_18px_32px_-26px_rgb(0_0_0_/_0.6)]"><a class="btn group w-full justify-between border-0" href="{{ downloads.primary.href }}"><span>{% if downloads.primary.label == "EPUB" %}Standard {% endif %}{{ downloads.primary.label }}</span><span class="ml-4 text-muted group-hover:text-paper">{{ downloads.primary.size }}</span></a>{% for download in downloads.others %}<a class="btn group w-full justify-between border-0" href="{{ download.href }}"><span>{{ download.label }}</span><span class="ml-4 text-muted group-hover:text-paper">{{ download.size }}</span></a>{% endfor %}</div></details></div>{% endif %}{% when None %}{% endmatch %}</div>{% endif %}
   <section class="mt-12" aria-labelledby="index-heading"><h2 id="index-heading" class="text-center text-3xl font-semibold leading-[1.1] tracking-[-0.01em]">In This Issue</h2>
-    {% for section in sections %}<section class="mt-14"><h3 class="reader-section-heading">{{ section.name }}</h3><ul class="m-0 list-none p-0">{% for entry in section.entries %}<li class="border-b border-rule py-6" data-toc-entry="{{ entry.href }}"><h4 class="font-serif font-semibold leading-[1.1] tracking-[-0.01em] {% if entry.is_lead %}text-3xl{% else %}text-2xl{% endif %}"><a class="text-ink no-underline hover:text-accent" href="{{ entry.href }}">{{ entry.title }}</a></h4><p class="mt-2 font-sans text-sm text-muted">{{ entry.source }} · {{ entry.reading_minutes }} min read{% if page.is_admin() %} · <a class="text-muted hover:text-accent" href="{{ entry.dashboard_href }}">dashboard</a>{% endif %}</p>{% if !entry.summary.is_empty() %}<p class="index-summary mt-4">{{ entry.summary }}</p>{% endif %}{% match entry.why %}{% when Some with (why) %}<p class="mt-4 border-l-2 border-accent pl-3 italic text-ink-2">Why it's here: {{ why }}</p>{% when None %}{% endmatch %}{% match entry.rating %}{% when Some with (widget) %}{% include "_rating_widget.html" %}{% when None %}{% endmatch %}</li>{% endfor %}</ul></section>{% endfor %}
+    {% for section in sections %}<section class="mt-14"><h3 class="reader-section-heading">{{ section.name }}</h3><ul class="m-0 list-none p-0">{% for entry in section.entries %}<li class="border-b border-rule py-6" data-toc-entry="{{ entry.href }}"><h4 class="font-serif font-semibold leading-[1.1] tracking-[-0.01em] {% if entry.is_lead %}text-3xl{% else %}text-2xl{% endif %}"><a class="text-ink no-underline hover:text-accent" href="{{ entry.href }}">{{ entry.title }}</a></h4><p class="mt-2 font-sans text-sm text-muted">{{ entry.source }} · {{ entry.reading_minutes }} min read{% if page.is_admin() %} · <a class="text-muted hover:text-accent" href="{{ entry.dashboard_href }}">dashboard</a>{% endif %}</p>{% if !entry.summary.is_empty() %}<p class="index-summary mt-4">{{ entry.summary }}</p>{% endif %}{% match entry.why %}{% when Some with (why) %}<p class="mt-4 border-l-2 border-accent pl-3 italic text-ink-2">Why it's here: {{ why }}</p>{% when None %}{% endmatch %}{% match entry.understanding %}{% when Some with (line) %}<p class="mt-3 font-sans text-sm text-muted">{{ line }}</p>{% when None %}{% endmatch %}{% match entry.rating %}{% when Some with (widget) %}{% include "_rating_widget.html" %}{% when None %}{% endmatch %}</li>{% endfor %}</ul></section>{% endfor %}
   </section>
   {% if has_world || has_behind %}<nav class="my-12 flex flex-wrap items-center justify-center gap-x-3 gap-y-1 border-y border-rule py-4 text-center font-sans text-sm uppercase tracking-[0.08em]" aria-label="Issue chapters">{% if has_world %}<a class="text-ink no-underline hover:text-accent" href="/issues/{{ date }}/world">World Briefing</a>{% endif %}{% if has_world && has_behind %}<span class="text-muted" aria-hidden="true">·</span>{% endif %}{% if has_behind %}<a class="text-ink no-underline hover:text-accent" href="/issues/{{ date }}/behind">Behind the paper</a>{% endif %}</nav>{% endif %}
   <footer id="colophon" class="mt-14 scroll-mt-6 font-sans text-sm leading-relaxed" data-toc-entry="/issues/{{ date }}#colophon"><h2 class="reader-section-heading">Colophon</h2><p class="my-4 text-ink-2"><em>The Daily EPUB</em> is assembled every morning from a personal feed reader.</p><dl class="kv border-y border-rule py-4 text-xs sm:text-sm"><dt>Generated</dt><dd>{{ colophon.generated_at }}</dd><dt>Bulk model</dt><dd>{{ colophon.bulk_model }}</dd><dt>Editor model</dt><dd>{{ colophon.editor_model }}</dd><dt>Summaries model</dt><dd>{{ colophon.summaries_model }}</dd><dt>Entries considered</dt><dd>{% match colophon.entries_fetched %}{% when Some with (entries) %}{{ entries }}{% match colophon.feeds_seen %}{% when Some with (feeds) %} from {{ feeds }} feeds{% when None %}{% endmatch %}{% when None %}n/a{% endmatch %}</dd><dt>Candidates scored</dt><dd>{% match colophon.candidates %}{% when Some with (candidates) %}{{ candidates }}{% when None %}n/a{% endmatch %}</dd><dt>Articles selected</dt><dd>{{ colophon.article_count }} across {{ colophon.section_count }} sections</dd><dt>Words</dt><dd>{{ colophon.total_words }} · ~{{ colophon.reading_minutes }} min read</dd>{% for cost in colophon.provider_costs %}<dt>{{ cost.provider }} cost</dt><dd>{{ cost.cost }}</dd>{% endfor %}<dt>Total token cost</dt><dd>{% match colophon.cost_usd %}{% when Some with (cost) %}{{ cost }}{% when None %}n/a{% endmatch %}</dd><dt>Generator</dt><dd>{{ colophon.generator_version }}</dd></dl></footer>

src/web/templates/issue_public.html

@@ -4,6 +4,6 @@
   <header class="mb-10 text-center"><p class="font-sans text-[0.72rem] uppercase tracking-[0.12em] text-muted">{{ issue.display_date }} · No. {{ issue.issue_number }}</p><p class="mt-2 font-sans text-sm text-muted">{{ issue.stats_line }}</p><p class="mx-auto mt-5 max-w-[58ch] text-lg italic leading-relaxed text-ink-2">A personal morning paper, assembled daily; the selection is the reader's, the words are the authors'.</p></header>
   <p class="notice mb-8"><a href="/login">Sign in</a> to read every article's full text and download the editions, or <a href="/request-access">request access</a>.</p>
   {% if !downloads.is_empty() %}<div class="mb-8 flex flex-wrap justify-center gap-2">{% for download in downloads %}<a class="btn" href="{{ download.href }}">{{ download.label }} <span class="ml-1 text-muted">{{ download.size }}</span></a>{% endfor %}</div>{% endif %}
-  {% for section in issue.sections %}<section class="mt-14"><h2 class="reader-section-heading">{{ section.name }}</h2><div>{% for entry in section.entries %}<article class="border-b border-rule py-6{% if entry.is_lead %} pt-5{% endif %}"><h3 class="font-semibold leading-[1.1] tracking-[-0.01em] {% if entry.is_lead %}text-3xl{% else %}text-2xl{% endif %}"><a class="text-ink no-underline hover:text-accent" href="{{ entry.url }}">{{ entry.title }}</a></h3><p class="mt-2 font-sans text-sm leading-relaxed text-muted">{% match entry.author %}{% when Some with (author) %}{{ author }} · {% when None %}{% endmatch %}{{ entry.source }}{% if !entry.domain.is_empty() %} ({{ entry.domain }}){% endif %} · {{ entry.reading_minutes }} min</p>{% match entry.summary %}{% when Some with (summary) %}<p class="index-summary mt-4">{{ summary }}</p>{% when None %}{% endmatch %}{% match entry.why %}{% when Some with (why) %}<p class="mt-4 border-l-2 border-accent pl-3 italic text-ink-2">Why it's here: {{ why }}</p>{% when None %}{% endmatch %}{% if !entry.comment_links.is_empty() %}<p class="mt-3 flex flex-wrap gap-x-4 gap-y-1 font-sans text-sm text-muted">{% for link in entry.comment_links %}<a class="text-muted hover:text-accent" rel="noopener" target="_blank" href="{{ link.url }}">{{ link.label }}{% if !link.meta.is_empty() %}: {{ link.meta }}{% endif %}</a>{% endfor %}</p>{% endif %}</article>{% endfor %}</div></section>{% endfor %}
+  {% for section in issue.sections %}<section class="mt-14"><h2 class="reader-section-heading">{{ section.name }}</h2><div>{% for entry in section.entries %}<article class="border-b border-rule py-6{% if entry.is_lead %} pt-5{% endif %}"><h3 class="font-semibold leading-[1.1] tracking-[-0.01em] {% if entry.is_lead %}text-3xl{% else %}text-2xl{% endif %}"><a class="text-ink no-underline hover:text-accent" href="{{ entry.url }}">{{ entry.title }}</a></h3><p class="mt-2 font-sans text-sm leading-relaxed text-muted">{% match entry.author %}{% when Some with (author) %}{{ author }} · {% when None %}{% endmatch %}{{ entry.source }}{% if !entry.domain.is_empty() %} ({{ entry.domain }}){% endif %} · {{ entry.reading_minutes }} min</p>{% match entry.summary %}{% when Some with (summary) %}<p class="index-summary mt-4">{{ summary }}</p>{% when None %}{% endmatch %}{% match entry.why %}{% when Some with (why) %}<p class="mt-4 border-l-2 border-accent pl-3 italic text-ink-2">Why it's here: {{ why }}</p>{% when None %}{% endmatch %}{% match entry.understanding %}{% when Some with (line) %}<p class="mt-3 font-sans text-sm text-muted">{{ line }}</p>{% when None %}{% endmatch %}{% if !entry.comment_links.is_empty() %}<p class="mt-3 flex flex-wrap gap-x-4 gap-y-1 font-sans text-sm text-muted">{% for link in entry.comment_links %}<a class="text-muted hover:text-accent" rel="noopener" target="_blank" href="{{ link.url }}">{{ link.label }}{% if !link.meta.is_empty() %}: {{ link.meta }}{% endif %}</a>{% endfor %}</p>{% endif %}</article>{% endfor %}</div></section>{% endfor %}
   <p class="mt-10 text-center font-sans text-sm"><a href="/issues">Browse the archive →</a></p>
 {% endif %}</article>{% endblock %}