delete sampleArticles seed; serve all sections from bb.wp_imported_posts (DB)

Eliminates 72 hardcoded rocket.new image refs in one shot. Section pages
(/gear, /technology, /show-coverage, /news) now render from
bb.wp_imported_posts via getLegacyArticlesBySection(section), which maps
each non-news section to a curated tag set (e.g. gear -> Audio, Cameras,
lighting, Blackmagic Design, monitoring; technology -> AI, Streaming,
OTT, IP, Cloud, AV; show-coverage -> NAB, IBC, BroadcastAsia).

Also:
- src/lib/articles/types.ts: Article interface lifted out of the deleted
  seed file. Type-only consumers (NewsArticleDetailClient,
  ArticleDetailClient, legacy-source) re-imported from here.
- /news (client component) now wrapped: server fetches articles from DB
  and passes to NewsPageClient. Filter UI unchanged.
- generateStaticParams on /news/[slug] and /articles/[slug] no longer
  references seed slugs; pre-renders 50 most-recent imported slugs and
  relies on dynamicParams + revalidate=3600 for the rest.
- sitemap.ts now sources article URLs from
  getLegacyRecentSitemapEntries() (up to 5000 most-recent imported posts).
  Default BASE_URL fallback updated from the rocket.new placeholder to
  bb-staging.onsethost.com.
- src/app/api/ai/article-suggestions/route.ts now pulls candidates from
  the DB (top 100 recent news) and resolves AI-returned slugs via DB
  lookup if not in the candidate window.

Inline rocket.new image refs in homepage components (ArticleFeed,
FeaturedBento) are unchanged in this commit; those are inline seed
arrays in the components, not imports of sampleArticles.

src/app/api/ai/article-suggestions/route.ts

@@ -1,22 +1,26 @@
 import { NextRequest, NextResponse } from 'next/server';
 import { hybridAI } from '@/lib/ai/hybridRouter';
-import { sampleArticles } from '@/lib/articles/sampleArticles';
+import {
+  getLegacyArticlesBySection,
+  getLegacyArticleBySlug,
+} from '@/lib/articles/legacy-source';
 
 export async function POST(request: NextRequest) {
   try {
     const { interests, readingHistory } = await request.json();
 
-    // Build a compact article index for the AI to reason over
-    const articleIndex = sampleArticles
-      .filter((a) => a.section === 'news')
-      .map((a) => ({
-        slug: a.slug,
-        title: a.title,
-        excerpt: a.excerpt,
-        tags: a.tags,
-        category: a.category,
-        date: a.date,
-      }));
+    // Pull a recent slice of news for the AI to choose from. Cap at 100 so the
+    // prompt stays bounded.
+    const news = await getLegacyArticlesBySection('news', 100);
+
+    const articleIndex = news.map((a) => ({
+      slug: a.slug,
+      title: a.title,
+      excerpt: a.excerpt,
+      tags: a.tags,
+      category: a.category,
+      date: a.date,
+    }));
 
     const systemPrompt = `You are a personalized content recommendation engine for BroadcastBeat, a broadcast engineering news platform.
 Given a reader's topic interests and reading history, select the 4 most relevant articles from the provided article list.
@@ -36,45 +40,38 @@ Return the 4 most relevant article slugs as a JSON array.`;
         { role: 'system', content: systemPrompt },
         { role: 'user', content: userPrompt },
       ],
-      {
-        maxTokens: 200,
-        temperature: 0.3,
-        priority: 4,
-      }
+      { maxTokens: 200, temperature: 0.3, priority: 4 }
     );
 
     const content = result.text;
 
     let slugs: string[] = [];
     try {
-      // Extract JSON array from response (model may wrap it in text)
       const match = content.match(/\[[\s\S]*?\]/);
       slugs = match ? JSON.parse(match[0]) : JSON.parse(content.trim());
     } catch {
-      // Fallback: extract slugs with regex
       const matches = content.match(/"([^"]+)"/g);
       slugs = matches ? matches.map((m: string) => m.replace(/"/g, '')).slice(0, 4) : [];
     }
 
-    // Resolve full article objects
-    const suggested = slugs
-      .map((slug: string) => sampleArticles.find((a) => a.slug === slug))
-      .filter(Boolean)
-      .slice(0, 4);
+    // Resolve from the candidate set first; if a slug wasn't in the recent
+    // window, look it up via DB so AI hallucinations or older slugs still resolve.
+    const suggested = (
+      await Promise.all(
+        slugs.slice(0, 4).map(async (slug: string) =>
+          news.find((a) => a.slug === slug) || (await getLegacyArticleBySlug(slug))
+        )
+      )
+    ).filter(Boolean);
 
-    // Fallback: return latest news if AI returned nothing useful
     if (suggested.length === 0) {
-      const fallback = sampleArticles
-        .filter((a) => a.section === 'news')
-        .slice(0, 4);
-      return NextResponse.json({ suggestions: fallback });
+      return NextResponse.json({ suggestions: news.slice(0, 4) });
     }
 
     return NextResponse.json({ suggestions: suggested });
   } catch (error) {
     console.error('Article suggestions error:', error);
-    // Graceful fallback
-    const fallback = sampleArticles.filter((a) => a.section === 'news').slice(0, 4);
+    const fallback = await getLegacyArticlesBySection('news', 4);
     return NextResponse.json({ suggestions: fallback });
   }
 }