Add job board scraper: modular scrapers, SQLite storage, web UI

Scrapes slo-tech.com (Ljubljana) every 24h, stores jobs in SQLite and
tracks which are new vs. seen. New sites can be added as modules in
src/scrapers/.

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

scrapper/src/scrapers/http.ts

@@ -0,0 +1,45 @@
+// Shared helpers for scrapers.
+
+const USER_AGENT =
+  "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0 Safari/537.36";
+
+// Upper half (0xA0-0xFF) of ISO-8859-2, which Bun's TextDecoder does not support.
+const LATIN2_HIGH =
+  " Ą˘Ł¤ĽŚ§¨ŠŞŤŹ­ŽŻ°ą˛ł´ľśˇ¸šşťź˝žżŔÁÂĂÄĹĆÇČÉĘËĚÍÎĎĐŃŇÓÔŐÖ×ŘŮÚŰÜÝŢßŕáâăäĺćçčéęëěíîďđńňóôőö÷řůúűüýţ˙";
+
+function decodeLatin2(bytes: Uint8Array): string {
+  let out = "";
+  for (const b of bytes) out += b < 0xa0 ? String.fromCharCode(b) : LATIN2_HIGH[b - 0xa0];
+  return out;
+}
+
+/** Fetch a page and decode it according to its declared charset. */
+export async function fetchHtml(url: string): Promise<string> {
+  const res = await fetch(url, { headers: { "User-Agent": USER_AGENT } });
+  if (!res.ok) throw new Error(`GET ${url} -> HTTP ${res.status}`);
+  const bytes = new Uint8Array(await res.arrayBuffer());
+  const charset = /charset=([\w-]+)/i.exec(res.headers.get("content-type") ?? "")?.[1]?.toLowerCase() ?? "utf-8";
+  if (charset === "iso-8859-2" || charset === "latin2") return decodeLatin2(bytes);
+  try {
+    return new TextDecoder(charset).decode(bytes);
+  } catch {
+    return new TextDecoder("utf-8").decode(bytes);
+  }
+}
+
+const NAMED_ENTITIES: Record<string, string> = {
+  amp: "&", lt: "<", gt: ">", quot: '"', apos: "'", nbsp: " ", raquo: "»", laquo: "«",
+};
+
+/** Decode HTML entities (HTMLRewriter text chunks are not decoded). */
+export function decodeEntities(s: string): string {
+  return s.replace(/&(#x[0-9a-f]+|#\d+|\w+);/gi, (m, e: string) => {
+    if (e[0] === "#") {
+      const code = e[1] === "x" || e[1] === "X" ? parseInt(e.slice(2), 16) : parseInt(e.slice(1), 10);
+      return Number.isFinite(code) ? String.fromCodePoint(code) : m;
+    }
+    return NAMED_ENTITIES[e.toLowerCase()] ?? m;
+  });
+}
+
+export const clean = (s: string) => decodeEntities(s).replace(/\s+/g, " ").trim();