feat: show current chapter in Continue reading cards

Each card in the Continue reading section now displays the saved chapter
number (e.g. 'Chapter 42') in amber below the author line, read from
localStorage.reading_progress.

scraper/internal/server/ui.go

@@ -202,6 +202,22 @@ const homeTmpl = `
     var card = document.querySelector('[data-slug="' + slug + '"]');
     if (!card) return;
     var clone = card.cloneNode(true);
+    // Inject "Chapter N" line into the cloned card
+    var chapterNum = progress[slug];
+    var meta = clone.querySelector('.min-w-0');
+    if (meta && chapterNum) {
+      var chLine = document.createElement('p');
+      chLine.className = 'text-xs text-amber-400 mt-1';
+      chLine.textContent = 'Chapter ' + chapterNum;
+      // Insert after the author line (second child) or after the title
+      var author = meta.querySelector('p');
+      if (author) {
+        author.insertAdjacentElement('afterend', chLine);
+      } else {
+        var title = meta.querySelector('h2');
+        if (title) title.insertAdjacentElement('afterend', chLine);
+      }
+    }
     continueGrid.appendChild(clone);
     card.parentNode.removeChild(card);
     moved++;