feat(search): add SearXNG client with whitelist-filtered web search

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

src/lib/server/search/searxng.ts

@@ -0,0 +1,78 @@
+import type Database from 'better-sqlite3';
+import { listDomains, normalizeDomain } from '../domains/repository';
+import { fetchText } from '../http';
+
+export type WebHit = {
+  url: string;
+  title: string;
+  domain: string;
+  snippet: string | null;
+  thumbnail: string | null;
+};
+
+type SearxngResult = {
+  url: string;
+  title: string;
+  content?: string;
+  thumbnail?: string;
+  img_src?: string;
+};
+
+type SearxngResponse = {
+  results?: SearxngResult[];
+};
+
+function hostnameFromUrl(url: string): string | null {
+  try {
+    return normalizeDomain(new URL(url).hostname);
+  } catch {
+    return null;
+  }
+}
+
+export async function searchWeb(
+  db: Database.Database,
+  query: string,
+  opts: { searxngUrl?: string; limit?: number } = {}
+): Promise<WebHit[]> {
+  const trimmed = query.trim();
+  if (!trimmed) return [];
+  const domains = listDomains(db).map((d) => d.domain);
+  if (domains.length === 0) return [];
+
+  const searxngUrl = opts.searxngUrl ?? process.env.SEARXNG_URL ?? 'http://localhost:8888';
+  const limit = opts.limit ?? 20;
+  const siteFilter = domains.map((d) => `site:${d}`).join(' OR ');
+  const q = `${trimmed} (${siteFilter})`;
+  const endpoint = new URL('/search', searxngUrl);
+  endpoint.searchParams.set('q', q);
+  endpoint.searchParams.set('format', 'json');
+  endpoint.searchParams.set('language', 'de');
+
+  const body = await fetchText(endpoint.toString(), { timeoutMs: 15_000 });
+  let parsed: SearxngResponse;
+  try {
+    parsed = JSON.parse(body) as SearxngResponse;
+  } catch {
+    throw new Error('SearXNG did not return JSON');
+  }
+  const results = parsed.results ?? [];
+  const allowed = new Set(domains);
+  const seen = new Set<string>();
+  const hits: WebHit[] = [];
+  for (const r of results) {
+    const host = hostnameFromUrl(r.url);
+    if (!host || !allowed.has(host)) continue;
+    if (seen.has(r.url)) continue;
+    seen.add(r.url);
+    hits.push({
+      url: r.url,
+      title: r.title,
+      domain: host,
+      snippet: r.content ?? null,
+      thumbnail: r.thumbnail ?? r.img_src ?? null
+    });
+    if (hits.length >= limit) break;
+  }
+  return hits;
+}