Threading: Antworten (reply_to) + Focus-View

- entry: reply_to/reply_count/last_activity; reply_count bubbelt bis Root
- Hauptfeed nur Roots nach last_activity, Profil-Feed inkl. Antworten
- GET /entry/{pid}/thread (Ahnen+Antworten), GET /e/{pid} Focus-Seite
- Frontend: Antworten-Link im Feed, entry.html/entry.js Focus-Seite
- notes/migrations.md: ALTER TABLE fuer Prod

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/js/entry.js

@@ -0,0 +1,55 @@
+"use strict";
+
+// pid aus dem Pfad /e/<pid>.
+const pid = location.pathname.split("/")[2] || "";
+
+document.getElementById("reply-form").addEventListener("submit", async (e) => {
+  e.preventDefault();
+  const fd = new FormData(e.target);
+  fd.append("reply_to", pid);
+  const res = await api.post("/entry/create", fd);
+  if (res.ok) {
+    e.target.reset();
+    document.getElementById("reply-msg").textContent = "";
+    load();
+  } else {
+    document.getElementById("reply-msg").textContent =
+      res.data.error || "Antwort fehlgeschlagen.";
+  }
+});
+
+async function load() {
+  const data = await api.get(`/entry/${pid}/thread`);
+
+  const focus = document.getElementById("focus");
+  if (data.error) {
+    focus.textContent = "Beitrag nicht gefunden";
+    return;
+  }
+
+  // Ahnenkette (Root zuerst), dann der fokussierte Beitrag.
+  const ancestors = document.getElementById("ancestors");
+  ancestors.innerHTML = "";
+  data.ancestors.forEach((a) => ancestors.appendChild(renderEntry(a)));
+
+  focus.innerHTML = "";
+  focus.appendChild(renderEntry(data.entry));
+
+  // Reply-Box nur eingeloggt zeigen.
+  const h = await api.get("/auth/headerbar");
+  document.getElementById("reply-box").hidden = !h.loggedin;
+
+  // Direkte Antworten.
+  const replies = document.getElementById("replies");
+  replies.innerHTML = "";
+  if (!data.replies.length) {
+    const p = document.createElement("p");
+    p.className = "muted";
+    p.textContent = "Noch keine Antworten.";
+    replies.appendChild(p);
+  } else {
+    data.replies.forEach((e) => replies.appendChild(renderEntry(e)));
+  }
+}
+
+load();