Reclassify sub-5s visits as crawlers, show crawler referers and abuser articles.

Visits with under 5 s of total reported reading time are JS-running bots:
display() converts them to crawler hits (one per trail page, with referer
and UTM query) and excludes them from every aggregate.  Crawler referers
join the favicon fetch origins and render with their icon in the crawler
table.  Abuse hits now record the real response status, so the abuse table
splits 404 probes from the articles the abuser actually read (200 GETs),
shown as trail links like the visitor/crawler tables.

frontend/src/AnalyticsView.vue

@@ -163,7 +163,7 @@ const favicons = computed(() => data.value?.favicons || {})
 const visitRows = computed(() => formatVisitRows(visits.value, clients.value, pageTree.value, now.value))
 const crawlers = computed(() => rangeData.value?.crawlers || [])
 const crawlerRows = computed(() => formatCrawlerRows(crawlers.value, clients.value, pageTree.value, now.value))
-const abuseRows = computed(() => formatAbuseRows(rangeData.value?.abuse || [], clients.value, now.value))
+const abuseRows = computed(() => formatAbuseRows(rangeData.value?.abuse || [], clients.value, pageTree.value, now.value))
 
 </script>
 
@@ -244,6 +244,7 @@ const abuseRows = computed(() => formatAbuseRows(rangeData.value?.abuse || [], c
               <tbody>
                 <tr v-for="(c, i) in crawlerRows" :key="i">
                   <td class="trail">
+                    <TrailLink v-if="c.refererStep" :step="c.refererStep" :favicons="favicons" @close="$emit('close')" />
                     <TrailLink v-for="(s, si) in c.pages" :key="si" :step="s" :count="s.count" @close="$emit('close')" />
                   </td>
                   <VisitorCell
@@ -270,6 +271,7 @@ const abuseRows = computed(() => formatAbuseRows(rangeData.value?.abuse || [], c
               <thead>
                 <tr>
                   <th>paths abused</th>
+                  <th>articles read</th>
                   <th>visitor</th>
                   <th class="last-seen">last seen</th>
                 </tr>
@@ -286,6 +288,11 @@ const abuseRows = computed(() => formatAbuseRows(rangeData.value?.abuse || [], c
                       <small v-if="a.paths.length > ABUSE_MAX_LINES" class="muted">+{{ a.paths.length - ABUSE_MAX_LINES }} more</small>
                     </div>
                   </td>
+                  <td class="trail clickable-list"
+                      @click="copyList(a.allArticles, $event)">
+                    <TrailLink v-for="(s, si) in a.articles" :key="si" :step="s" :count="s.count" @close="$emit('close')" />
+                    <small v-if="!a.articles.length" class="muted">—</small>
+                  </td>
                   <VisitorCell
                     :ip="a.ip"
                     :ip-display="a.ipDisplay"