Add Optius scraper via its official RSS feed

Optius publishes an RSS feed with region/field filters, so no HTML
scraping is needed. Also move the duplicated slug helper into http.ts
(output unchanged, so existing source IDs and URLs are unaffected).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scrapper/src/scrapers/optius.ts

@@ -0,0 +1,42 @@
+import { clean, fetchHtml, slugify } from "./http";
+import type { ScrapedJob, Scraper } from "./types";
+
+// Optius publishes an official RSS feed with region/field filters, so no HTML scraping is needed.
+// Build a feed URL at https://www.optius.com/rss/ (its IDs differ from the search page's IDs).
+
+const tag = (xml: string, name: string) => new RegExp(`<${name}[^>]*>([\\s\\S]*?)</${name}>`).exec(xml)?.[1];
+const text = (s: string | undefined) => clean((s ?? "").replace(/^<!\[CDATA\[([\s\S]*)\]\]>$/, "$1"));
+
+export function parseOptiusFeed(xml: string): ScrapedJob[] {
+  return [...xml.matchAll(/<item>([\s\S]*?)<\/item>/g)]
+    .map((m): ScrapedJob | null => {
+      const item = m[1]!;
+      const url = text(tag(item, "link") ?? tag(item, "guid"));
+      const id = /-(\d+)-\1\/?$/.exec(url)?.[1] ?? /-(\d+)\/?$/.exec(url)?.[1];
+      const title = text(tag(item, "title"));
+      if (!id || !title) return null;
+      const pubDate = tag(item, "pubDate");
+      return {
+        externalId: id,
+        title,
+        url,
+        company: text(tag(item, "employer")) || undefined,
+        tags: [...item.matchAll(/<field(?:\s[^>]*)?>([\s\S]*?)<\/field>/g)].map((f) => text(f[1])).filter(Boolean),
+        postedAt: pubDate ? new Date(pubDate).toISOString() : undefined,
+      };
+    })
+    .filter((j): j is ScrapedJob => j !== null);
+}
+
+/** Scraper for an optius.com RSS feed, e.g. "https://www.optius.com/rss/?regija=7&podrocje=7". */
+export function optius(label: string, feedUrl: string): Scraper {
+  return {
+    id: `optius-${label.normalize("NFD").replace(/[̀-ͯ]/g, "").replace(/[^A-Za-z0-9]+/g, "-").replace(/^-|-$/g, "").toLowerCase()}`,
+    name: `Optius (${label})`,
+    async scrape() {
+      const xml = await fetchHtml(feedUrl);
+      if (!xml.includes("<rss")) throw new Error("response is not an RSS feed (site changed?)");
+      return parseOptiusFeed(xml);
+    },
+  };
+}