Add Spark Control hardware backend (diarize, queue, discovery)

server/lan-fetch.js

@@ -0,0 +1,41 @@
+// TLS-tolerant fetch for LAN calls to operator-managed services that
+// use StartOS Local Intermediate CA certs (or other self-signed certs)
+// the relay container doesn't trust by default.
+//
+// Scope: Spark Control discovery + diarize-chunk POST. Those are the
+// only HTTPS endpoints the relay talks to over the operator's own
+// LAN. Public-internet calls (Gemini, Keysat, BTCPay) keep going
+// through the normal global fetch with full cert validation — we
+// don't pipe those through this helper.
+//
+// Safety: the URL passed in came from the operator's own config
+// (Service Discovery URL field). The relay isn't auto-discovering or
+// following untrusted redirects to arbitrary hosts.
+//
+// Implementation: undici's Agent supports per-dispatcher
+// rejectUnauthorized control; Node's built-in fetch globally does
+// not. We construct one Agent at module init and pass it as the
+// dispatcher on every call.
+
+import { Agent, fetch as undiciFetch } from "undici";
+
+const lanAgent = new Agent({
+  connect: { rejectUnauthorized: false },
+  // 5s for TCP+TLS handshake — long enough for cold StartOS sockets,
+  // short enough to fail fast on a bad URL.
+  connectTimeout: 5000,
+  // Diarize-chunk and transcribe on the operator's GPU box are slow
+  // (Sortformer + TitaNet on a 5-min chunk can run 30-120s before
+  // SC sends back response headers). headersTimeout/bodyTimeout = 0
+  // disables undici's own watchdog — we rely entirely on the
+  // AbortSignal.timeout the caller passes (900s by default for
+  // hardware backend calls). Without this, lanFetch was killing the
+  // connection at 10s with a bare "fetch failed" before SC had any
+  // chance to respond.
+  headersTimeout: 0,
+  bodyTimeout: 0,
+});
+
+export async function lanFetch(url, opts = {}) {
+  return undiciFetch(url, { ...opts, dispatcher: lanAgent });
+}