ncm A2: 音频输出迁移 meow_audiod（SINK_AUDIOD 默认后端）— 修无声根因

- audio_out.c: 新增 SINK_AUDIOD 默认（SDK meow_audio_* 连 audiod）；NCM_AUDIO_SINK=file/null/alsa
  与 MEOW_AUDIO_DIRECT=1 保留调试后端；ALSA 保底修两大坑（hw_params 全放行初始化 + mask 清零
  再单点）——旧 memset0 interval=「只能取0」→ HW_PARAMS 恒 EINVAL 即播放无声根因
- 新增 audio_out_pause：PAUSED 沿向 audiod 发 pause（停时钟不丢流）；resume 流死自动重开
- player_manager: 注册 meow_audio_on_preempt → g_play 命令通道暂停；播放事件全量 meow_log
  （open 参数/grant_*/write 错误节流/切歌/暂停/seek/done）
- appstate/app: /tmp/ncm_autoplay 真机联调 hook（仅播已缓存曲目，绝不发 song_url）
- bench/audiod_chain_sim.c: 真实 audiod_host 假 socket 全链离线回归 14 项全 PASS
- 验证: host 0 warning / WAV 回归 / qemu core PASS / mipsel 0 warning；真机 OPEN→grant 已通，
  持续写帧被 M2.90 设备 PCM 播放内核硬挂死阻断（REPORT §16.3，4/4 复现，留主会话）
- ncm md5 db5b78ad9e8f40e6306484efe2a08eb3（已热更设备）

patch_v2/ncm_app/app/play/player_manager.c

@@ -26,6 +26,15 @@ static int64_t   g_file_bytes;
 static int       g_level;            /* 音质档（来自设置） */
 static int       g_cache_gb;
 
+/* 被抢占回调（SDK 读线程分发；audiod 后开流赢）：走 g_play 命令通道暂停（内部持锁），
+ * 不直接动锁外状态。恢复时 audio_out_pause(0) 会检测流死并自动重开（见 audio_out.c）。 */
+static void on_audio_preempt(const char *by_app, void *ctx)
+{
+    (void)ctx;
+    meow_log(MEOW_LOG_WARN, "play: preempted by [%s] -> pause", (by_app && by_app[0]) ? by_app : "?");
+    player_manager_pause(1);
+}
+
 int player_manager_state(void) { int s; pthread_mutex_lock(&g_play.mu); s = g_play.state; pthread_mutex_unlock(&g_play.mu); return s; }
 int player_manager_playing_song(void) { int s; pthread_mutex_lock(&g_play.mu); s = g_play.cur_song; pthread_mutex_unlock(&g_play.mu); return s; }
 int64_t player_manager_pos_ms(void) { int64_t p; pthread_mutex_lock(&g_play.mu); p = g_play.pos_ms; pthread_mutex_unlock(&g_play.mu); return p; }
@@ -196,10 +205,12 @@ static void run_song(int idx)
     g_play.dur_ms = dur;
     g_play.err = 0;
     pthread_mutex_unlock(&g_play.mu);
+    meow_log(MEOW_LOG_INFO, "play: start idx=%d id=%s dur=%lldms", idx, s->id, (long long)dur);
 
     mp3d_sample_t pcm[PCM_CHUNK];
     int64_t frames_done = 0;          /* 已输出帧（每通道） */
     int need_seek_ms = -1;
+    int paused_edge = 0;              /* 暂停沿：进暂停已向 audiod 发 pause */
 
     for (;;) {
         if (g_app_quit) break;
@@ -212,15 +223,30 @@ static void run_song(int idx)
         int st  = g_play.state;
         pthread_mutex_unlock(&g_play.mu);
 
-        if (cur != idx) break;               /* 切歌 → 回外层 */
-        if (st == NCM_PC_STOPPED) break;
+        if (cur != idx) { meow_log(MEOW_LOG_INFO, "play: switch idx=%d -> %d", idx, cur); break; }   /* 切歌 → 回外层 */
+        if (st == NCM_PC_STOPPED) { meow_log(MEOW_LOG_INFO, "play: stopped idx=%d", idx); break; }
 
         if (cmd == NCM_CTL_SEEK && seek_ms >= 0) { need_seek_ms = (int)seek_ms; }
 
-        if (st == NCM_PC_PAUSED) { usleep(40 * 1000); continue; }   /* 冻结 */
+        if (st == NCM_PC_PAUSED) {
+            if (!paused_edge) {     /* 进暂停：停 PCM 时钟但不丢流（audiod MSG_AUDIO_PAUSE） */
+                paused_edge = 1;
+                meow_log(MEOW_LOG_INFO, "play: paused idx=%d pos=%lldms", idx,
+                         (long long)(frames_done * 1000 / 44100));
+                audio_out_pause(1);
+            }
+            usleep(40 * 1000);
+            continue;               /* 冻结 */
+        }
+        if (paused_edge) {          /* 出暂停：恢复 audiod 流（流死则自动重开） */
+            paused_edge = 0;
+            meow_log(MEOW_LOG_INFO, "play: resumed idx=%d", idx);
+            if (audio_out_pause(0) != 0) { set_err(NCM_ERR_IO, "audio resume failed"); break; }
+        }
 
         if (need_seek_ms >= 0) {
             /* 重开并 seek：关闭后重开（字节 offset 近似） */
+            meow_log(MEOW_LOG_INFO, "play: seek idx=%d -> %dms", idx, need_seek_ms);
             audio_out_close();
             mp3dec_ex_close(&dec);
             memset(&dec, 0, sizeof dec);
@@ -235,7 +261,10 @@ static void run_song(int idx)
         }
 
         size_t got = mp3dec_ex_read(&dec, pcm, PCM_CHUNK);
-        if (got == 0) break;                         /* 播完 */
+        if (got == 0) {             /* 播完 */
+            meow_log(MEOW_LOG_INFO, "play: done idx=%d frames=%lld", idx, (long long)frames_done);
+            break;
+        }
         int frames = (int)(got / 2);
         if (audio_out_write(pcm, frames) != frames)   break;
         frames_done += frames;
@@ -377,6 +406,7 @@ int player_manager_start(void)
     g_level = g_st.level;
     g_cache_gb = g_st.cache_limit_gb;
     pthread_mutex_init(&g_play.mu, NULL);
+    meow_audio_on_preempt(on_audio_preempt, NULL);   /* 被抢占 → 暂停（SDK 读线程分发） */
     if (pthread_create(&g_thr, NULL, player_thread, NULL) != 0) return -1;
     g_thr_on = 1;
     return 0;