articles: discussion threads + Related Forum Posts sidebar

ArticleComments component renders under every news + articles detail
page. Anonymous visitors see all existing comments and a Sign-in CTA;
signed-in members get a composer, threaded replies, and up/down votes.
AI personas are tagged with a small AI chip so readers know what
they're interacting with — same persona TZ rules from #63 apply.

Schema extensions on bb.article_comments: parent_comment_id self-FK
for one-level threading, denormalized author fields, vote counters,
is_ai_seeded flag, status enum. user_id relaxed to nullable so AI rows
can exist without a real user_profile; CHECK constraint enforces 'real
user OR is_ai_seeded' so anonymous comments can never sneak through.
forum_votes.target_type check expanded to include 'comment' — same
polymorphic vote table powers thread/reply/comment votes.

New Related Forum Posts sidebar on both /articles/[slug] and
/news/[slug]. getRelatedForumThreads() does title-keyword ILIKE OR
against forum_threads, ranked by reply_count + recency, with recently-
active fallback so the box is never empty. 6 threads per article.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/api/comments/route.ts

@@ -0,0 +1,100 @@
+/**
+ * Article comments API.
+ *
+ *   GET  /api/comments?article_slug=<slug>   → list, threaded by parent
+ *   POST /api/comments                       → create (auth required)
+ *
+ * Reads: public — anyone can fetch.
+ * Writes: signed-in users only. We assert via supabase auth and use the
+ *   user's forum_user_profile for the denormalized display fields so the
+ *   client can render avatar/name without an extra join per comment.
+ */
+import { NextRequest, NextResponse } from "next/server";
+import { createClient } from "@/lib/supabase/server";
+
+export const dynamic = "force-dynamic";
+
+interface Row {
+  id: string;
+  article_slug: string;
+  parent_comment_id: string | null;
+  user_id: string | null;
+  content: string;
+  author_username: string | null;
+  author_display_name: string | null;
+  author_avatar_url: string | null;
+  is_ai_seeded: boolean;
+  upvotes: number;
+  downvotes: number;
+  vote_score: number;
+  status: string;
+  created_at: string;
+  updated_at: string;
+}
+
+export async function GET(req: NextRequest) {
+  const slug = new URL(req.url).searchParams.get("article_slug");
+  if (!slug) return NextResponse.json({ error: "article_slug required" }, { status: 400 });
+
+  const sb = await createClient();
+  const { data, error } = await sb
+    .from("article_comments")
+    .select("*")
+    .eq("article_slug", slug)
+    .eq("status", "published")
+    .order("vote_score", { ascending: false })
+    .order("created_at", { ascending: true })
+    .limit(500);
+
+  if (error) return NextResponse.json({ error: error.message }, { status: 500 });
+  return NextResponse.json({ comments: data || [] });
+}
+
+export async function POST(req: NextRequest) {
+  const sb = await createClient();
+  const { data: { user } } = await sb.auth.getUser();
+  if (!user) {
+    return NextResponse.json(
+      { error: "Sign in to comment", redirectTo: "/forum/login" },
+      { status: 401 },
+    );
+  }
+  let body: { article_slug?: string; content?: string; parent_comment_id?: string | null };
+  try { body = await req.json(); }
+  catch { return NextResponse.json({ error: "Invalid JSON" }, { status: 400 }); }
+
+  const slug = (body.article_slug || "").trim();
+  const content = (body.content || "").trim();
+  if (!slug || !content) {
+    return NextResponse.json({ error: "article_slug and content required" }, { status: 400 });
+  }
+  if (content.length > 5000) {
+    return NextResponse.json({ error: "Comment too long (5000 char max)" }, { status: 400 });
+  }
+
+  // Pull the user's forum profile so we have display name + avatar for
+  // denormalized rendering (saves a per-comment join later).
+  const { data: prof } = await sb
+    .from("forum_user_profiles")
+    .select("username, display_name, avatar_url")
+    .eq("user_id", user.id)
+    .maybeSingle();
+
+  const ins = {
+    article_slug: slug,
+    user_id: user.id,
+    content,
+    parent_comment_id: body.parent_comment_id || null,
+    is_ai_seeded: false,
+    author_username: prof?.username || null,
+    author_display_name: prof?.display_name || user.email?.split("@")[0] || "Member",
+    author_avatar_url: prof?.avatar_url || null,
+  };
+  const { data, error } = await sb
+    .from("article_comments")
+    .insert(ins)
+    .select()
+    .single();
+  if (error) return NextResponse.json({ error: error.message }, { status: 500 });
+  return NextResponse.json({ comment: data });
+}