Add fsnebula.org and api mirrors

[Shivansps]

This should make knossos to try diferent mirror in case knossos cant not connect to the main one at startup.

fsnebula.space uses a cloudflare worker to redirect trafic, for the record ill leave the cloudflare worker the code here.

export default {
  async fetch(request) {
    const url = new URL(request.url);

    // Rute by path -> host real
    let origin;
    if (url.pathname.startsWith("/api/"))          origin = "https://api.fsnebula.org";
    else if (url.pathname.startsWith("/storage/")) origin = "https://dl.fsnebula.org";
    else                                           origin = "https://fsnebula.org";

    const target = origin + url.pathname + url.search;

    const req = new Request(target, {
      method: request.method,
      headers: request.headers,
      body: ["GET", "HEAD"].includes(request.method) ? undefined : request.body,
      redirect: "follow",
    });
    req.headers.delete("Host"); 

    const noCache = url.pathname.endsWith("repo_minimal.json") || url.pathname.startsWith("/api/");

    const resp = await fetch(req, noCache ? { cf: { cacheEverything: false, cacheTtl: 0 } } : undefined);

    const out = new Response(resp.body, resp);        // stream
    out.headers.set("Access-Control-Allow-Origin", "*");
    if (noCache) out.headers.set("Cache-Control", "no-store");
    return out;
  }
};