fix: force HTTP/1.1 via ALPNProtocols to prevent h2 framing mismatch

api.spotify.com negotiates HTTP/2 via TLS ALPN but https.request uses
HTTP/1.1 framing — the protocol mismatch silently hangs the connection.
wget on Alpine doesn't advertise h2 so it works fine. ALPNProtocols:
['http/1.1'] forces HTTP/1.1 on both ends.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/novasonic-server.js

@@ -78,6 +78,9 @@ function _fetchTimeout(url, opts = {}, ms = 10000) {
       hostname: u.hostname, port: 443,
       path: u.pathname + u.search,
       method: opts.method || 'GET',
+      // Force HTTP/1.1 — api.spotify.com negotiates h2 via ALPN but
+      // https.request uses HTTP/1.1 framing, causing a silent hang.
+      ALPNProtocols: ['http/1.1'],
       headers: {
         'User-Agent': 'NovaSonic/1.0',
         'Accept': 'application/json',