fix: full stderr logging per-line, scan embed page for GQL hash

- Log each Python stderr line separately (no 500-char truncation) so
  we can see exactly what's happening in the bundle scan
- Try embed page (open.spotify.com/embed/...) first for GQL hashes —
  focused app, fewer bundles, GQL chunks directly referenced
- Suppress noisy bundle-fetch errors to keep logs readable

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

backend/novasonic-server.js

@@ -359,7 +359,7 @@ async function _resolveSpotifyViaSpotdl(url) {
   const cleanUrl = url.split('?')[0];
   return new Promise((resolve, reject) => {
     execFile('python3', [scriptPath, cleanUrl], { timeout: 90000, maxBuffer: 10 * 1024 * 1024 }, (err, stdout, stderr) => {
-      if (stderr?.trim()) console.log('[spotdl-py]', stderr.trim().slice(0, 500));
+      if (stderr?.trim()) stderr.trim().split('\n').forEach(l => console.log('[py]', l));
       // Always try to parse stdout first — script outputs JSON even on error
       const out = stdout?.trim();
       if (out) {

backend/spotify_resolve.py

@@ -67,8 +67,8 @@ def _scan_bundles(session, js_urls, need_totp, need_ops):
                 if h:
                     gql_hashes[op] = h
                     eprint(f'[spotify] GQL hash {op}: {h[:16]}...')
-        except Exception as e:
-            eprint(f'[spotify] bundle error ({u[-40:]}): {e}')
+        except Exception:
+            pass  # skip failed bundles silently
     return totp_secret, totp_version, gql_hashes
 
 def get_token_and_hashes(session, sp_type, sp_id):
@@ -90,17 +90,23 @@ def get_token_and_hashes(session, sp_type, sp_id):
     if not totp_secret:
         raise Exception('TOTP secret not found')
 
-    # Step 2: resource page — find GQL hash (lazy-loaded playlist/album/track chunk)
+    # Step 2: try embed page — focused app, GQL chunks often directly referenced
     if GQL_OP not in gql_hashes:
-        eprint(f'[spotify] fetching {sp_type} page for GQL hash...')
+        for extra_url in [
+            f'https://open.spotify.com/embed/{sp_type}/{sp_id}?utm_source=generator',
+            f'https://open.spotify.com/{sp_type}/{sp_id}',
+        ]:
+            eprint(f'[spotify] scanning {extra_url[:60]} for GQL hash...')
             try:
-            page_url = f'https://open.spotify.com/{sp_type}/{sp_id}'
-            page_html = session.get(page_url, headers=page_headers, timeout=15).text
+                page_html = session.get(extra_url, headers=page_headers, timeout=15).text
                 extra_js = _collect_js_urls(page_html, seen)
-            _, _, extra_hashes = _scan_bundles(session, extra_js[:25], False, [GQL_OP])
+                eprint(f'[spotify] found {len(extra_js)} new JS URLs on that page')
+                _, _, extra_hashes = _scan_bundles(session, extra_js[:30], False, [GQL_OP])
                 gql_hashes.update(extra_hashes)
             except Exception as e:
                 eprint(f'[spotify] page scan error: {e}')
+            if GQL_OP in gql_hashes:
+                break
 
     st = session.get('https://open.spotify.com/api/server-time', headers={
         'Accept': 'application/json', 'Referer': 'https://open.spotify.com/',