news-digest: live-recompute source + desk counts; hide empty sections

The server-rendered .source-count / .desk-count badges were correct
at render time but went stale the moment the user hid anything —
"r/HOMELAB (4)" stayed at 4 even after all 4 items were hidden.
Worse, the entire source header still rendered with a (0) badge
once every item underneath was gone.

app.js gains a refreshCounts() pass that walks every .source and
.desk, recomputes the visible (non-.is-hidden) child count, updates
the badge text, and toggles an .is-empty class. CSS rule for
.source.is-empty and .desk.is-empty sets display:none so empty
groups collapse out entirely. Hooked into hideItem, restoreItem,
and the initial-paint hidden-set application.

stacks/news-digest/templates/app.js

@@ -61,6 +61,28 @@
     return r.json();
   }
 
+  /* ── live counts ─────────────────────────────────────────────────
+     The server-rendered .source-count and .desk-count badges are
+     accurate at render time, but they fall stale as soon as the user
+     hides anything. Recompute from the DOM whenever the visible set
+     changes. Empty sources / desks get an .is-empty class that hides
+     them entirely (no point showing "r/homelab (0)"). */
+
+  function refreshCounts() {
+    document.querySelectorAll(".source").forEach((src) => {
+      const visible = src.querySelectorAll(".item:not(.is-hidden)").length;
+      const badge = src.querySelector(".source-count");
+      if (badge) badge.textContent = String(visible);
+      src.classList.toggle("is-empty", visible === 0);
+    });
+    document.querySelectorAll(".desk").forEach((desk) => {
+      const visibleItems = desk.querySelectorAll(".item:not(.is-hidden)").length;
+      const badge = desk.querySelector(".desk-count");
+      if (badge) badge.textContent = `${visibleItems} items`;
+      desk.classList.toggle("is-empty", visibleItems === 0);
+    });
+  }
+
   /* ── tray rendering ─────────────────────────────────────────────── */
 
   function refreshTrayVisibility() {
@@ -122,6 +144,7 @@
     // Optimistic — flip class first, talk to server next.
     el.classList.add(HIDE_CLASS);
     addTrayRow(id, titleOf(el));
+    refreshCounts();
 
     try {
       await apiHide(id, true);
@@ -129,6 +152,7 @@
       console.warn("[digest] hide failed, rolling back:", e);
       el.classList.remove(HIDE_CLASS);
       removeTrayRow(id);
+      refreshCounts();
     }
   }
 
@@ -144,12 +168,14 @@
     }
     el.classList.remove(HIDE_CLASS);
     removeTrayRow(id);
+    refreshCounts();
     try {
       await apiHide(id, false);
     } catch (e) {
       console.warn("[digest] restore failed, re-hiding:", e);
       el.classList.add(HIDE_CLASS);
       addTrayRow(id, titleOf(el));
+      refreshCounts();
     }
   }
 
@@ -187,5 +213,6 @@
       }
     });
     if (trayHadAdditions) refreshTrayVisibility();
+    refreshCounts();
   });
 })();

stacks/news-digest/templates/style.css

@@ -632,6 +632,14 @@ a:hover { color: var(--accent); }
   display: none;
 }
 
+/* When every item in a .source (or every source in a .desk) is hidden,
+   collapse the whole header out — no point rendering "r/homelab (0)".
+   app.js applies .is-empty when the visible-count drops to zero. */
+.source.is-empty,
+.desk.is-empty {
+  display: none;
+}
+
 .hidden-tray {
   margin-top: 24px;
   padding: 14px 18px;