Step 7.5b2: Spotify Connect zeroconf and login work (PCM counted only)

- Zeroconf on our httpd (GET/POST /spotify_info, form body URL-decoded)
  and _spotify-connect._tcp via our mDNS (VERSION, CPath, Stack TXT).
- Session task: waits for the app's login blob, connects with the
  user's client ID/secret and the configured bitrate (96/160/320 ->
  OGG_VORBIS_*), SpircHandler, events logged; cspot exceptions caught.
  Starts when source.mode is spotify/auto and credentials are set.
- bell::bellGlobalLogger was NULL: every CSPOT_LOG crashed the board
  right after addUser (Load access fault in Session.cpp:67 /
  LoginBlob.cpp:58). cspot/bell logs now go to esp_log (UART + syslog);
  signed CDN URL tokens are cut from the log.
- esp_audio_codec's own Vorbis decoder clashed with bell's Tremor
  symbols: CONFIG_AUDIO_DECODER_VORBIS_SUPPORT / SIMPLE_DEC_OGG off.
- status.spotify_state from the session (waiting / connecting /
  connected / login failed / error / disabled / no client credentials).
- Verified from a Mac: device appears, "connected as <user>", access
  token fetched with the user's client credentials, track info, audio
  key, CDN URL (the step broken upstream), PCM decoded. Without
  backpressure a track decodes in ~26 s (b3 feeds the ring).

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

main/player.c

@@ -96,11 +96,7 @@ static void player_status(cJSON *st)
                         s_src == SRC_SPOTIFY ? "not implemented" : s_playing ? "playing" : "buffering";
     cJSON_AddStringToObject(st, "active_source", SRC_NAME[s_src]);
     cJSON_AddStringToObject(st, "source_state", state);
-    cJSON *src = cfg_get("source");
-    bool creds = cJSON_GetObjectItemCaseSensitive(src, "spotify_client_id")->valuestring[0] &&
-                 cJSON_GetObjectItemCaseSensitive(src, "spotify_client_secret")->valuestring[0];
-    cJSON_Delete(src);
-    cJSON_AddStringToObject(st, "spotify_state", creds ? "not implemented" : "no client credentials");
+    cJSON_AddStringToObject(st, "spotify_state", spotify_state());
     cJSON_AddNumberToObject(st, "buffer_ms", (double)(audio_ring_level() * 1000 / RATE));
 }
 
@@ -119,9 +115,7 @@ esp_err_t player_init(void)
     if (err != ESP_OK) {
         return err;
     }
-    cJSON *sc = cfg_get("source");
-    spotify_init(cJSON_GetObjectItemCaseSensitive(sc, "spotify_name")->valuestring);
-    cJSON_Delete(sc);
+    spotify_init();
         err = hls_start(decoder_feed);
     if (err != ESP_OK) {
         return err;