fix(ncm §20.3): 降级链账户/fee感知 auto_av —— 修「SQ 被跳过掉标准」（297）

根因：ncm_api_song_url_auto 无账户感知，依赖调用方按会员钳顶；若账户 VIP 态未就绪/
错钳到 EXHIGH，降级链从 EXHIGH 起步，LOSSLESS(无损 SQ) 被跳过，直接掉「标准」。
修法：新增 ncm_api_song_url_auto_av[_f]（§20.3 权威形态）：fee∈{1,4} 且非 CVIP →
NCM_ERR_VIP 零请求；按 account_vip 自钳顶(NONE→EXHIGH/CVIP→HIRES/SVIP→SURROUND)；
只试账户可访问档(ncm_api_level_gate<=vip)；落在最近可用档。原 auto/auto_f 行为零回归。
逐级尝试重构为共享 level_attempt（type/url 接受+静默降档采信）。
测试(bench/degrade_sim.c)：fee门禁5例 + auto_av矩阵 vip3×desired9×avail9=243例全PASS
+ 真机复现(CVIP+Hi-Res+有SQ无HiRes→落无损SQ flac)；原90例零回归。
验证：test_ncm_core_host+qemu-mipsel 全PASS；build_core/build_ncm -Wall -Wextra 0 warning。
新 ncm md5 1064a1d686390cc159f18296ee2980ee（未部署，留主会话）。
遗留：player_manager.c 仍调 auto（不传vip/fee），应改请 auto_av(account_vip()+fee)；
真机若仍掉标准需另查旧缓存 song_<id>_hires.mp3 复用或旧二进制。

patch_v2/ncm_app/bench/degrade_sim.c

@@ -66,6 +66,34 @@ static int total_calls(void)
     return n;
 }
 
+/* ---- §20.3 账户/fee 感知降级链（auto_av_f）期望模型 ----
+ * cap(vip)：NONE→EXHIGH / CVIP→HIRES / SVIP→SURROUND（与 account.c account_level_cap 同口径）。
+ * start = clamp(desired, STANDARD, cap)；只试 gate(lv)<=vip 的档；落在 lv<=avail 的最近可用档。 */
+static int cap_for_vip(int vip) {
+    switch (vip) {
+        case NCM_VIP_SVIP: return NCM_LEVEL_SURROUND;
+        case NCM_VIP_CVIP: return NCM_LEVEL_HIRES;
+        default:           return NCM_LEVEL_EXHIGH;
+    }
+}
+static int expect_land(int vip, int desired, int avail) {
+    int cap = cap_for_vip(vip);
+    int start = desired > cap ? cap : desired;
+    if (start < NCM_LEVEL_STANDARD) start = NCM_LEVEL_STANDARD;
+    for (int lv = start; lv >= NCM_LEVEL_STANDARD; lv--)
+        if (ncm_api_level_gate(lv) <= vip && lv <= avail) return lv;
+    return -1;
+}
+static int expect_tried(int vip, int desired, int best) {
+    int cap = cap_for_vip(vip);
+    int start = desired > cap ? cap : desired;
+    if (start < NCM_LEVEL_STANDARD) start = NCM_LEVEL_STANDARD;
+    int n = 0;
+    for (int lv = start; lv >= NCM_LEVEL_STANDARD; lv--)
+        if (ncm_api_level_gate(lv) <= vip && (best < 0 || lv >= best)) n++;
+    return n;
+}
+
 int main(void)
 {
     ncm_play_url_t u;
@@ -160,6 +188,63 @@ int main(void)
           "req surround, resp level=sky (歧义) -> eff=surround (got %d)", eff);
     g_resp_level = NULL;
 
+    printf("== 7) auto_av_f fee 门禁（§20.4：fee∈{1,4} 且非 CVIP → 零请求 NCM_ERR_VIP）==\n");
+    reset_calls(); g_avail_from = NCM_LEVEL_SURROUND; g_type = "mp3";
+    CHECK(ncm_api_song_url_auto_av_f("d", "c", "1", NCM_VIP_NONE, 1, NCM_LEVEL_HIRES, &u, &eff, fake_try)
+              == NCM_ERR_VIP && total_calls() == 0,
+          "fee=1 + NONE -> NCM_ERR_VIP (calls=%d)", total_calls());
+    CHECK(ncm_api_song_url_auto_av_f("d", "c", "1", NCM_VIP_NONE, 4, NCM_LEVEL_HIRES, &u, &eff, fake_try)
+              == NCM_ERR_VIP && total_calls() == 0,
+          "fee=4 + NONE -> NCM_ERR_VIP (calls=%d)", total_calls());
+    CHECK(ncm_api_song_url_auto_av_f("d", "c", "1", NCM_VIP_CVIP, 1, NCM_LEVEL_HIRES, &u, &eff, fake_try)
+              == NCM_OK, "fee=1 + CVIP -> 放行");
+    CHECK(ncm_api_song_url_auto_av_f("d", "c", "1", NCM_VIP_NONE, 8, NCM_LEVEL_HIRES, &u, &eff, fake_try)
+              == NCM_OK, "fee=8 + NONE -> 放行（免费听低音质）");
+    CHECK(ncm_api_song_url_auto_av_f("d", "c", "1", NCM_VIP_NONE, 0, NCM_LEVEL_HIRES, &u, &eff, fake_try)
+              == NCM_OK, "fee=0 + NONE -> 放行");
+
+    printf("== 8) auto_av_f 全矩阵: account_vip 3 x desired 9 x avail 9（钳顶+门槛+最近可用档）==\n");
+    int av_bad = 0, av_cases = 0;
+    for (int vip = NCM_VIP_NONE; vip <= NCM_VIP_SVIP; vip++) {
+        for (int desired = NCM_LEVEL_STANDARD; desired <= NCM_LEVEL_SURROUND; desired++) {
+            for (int avail = NCM_LEVEL_STANDARD; avail <= NCM_LEVEL_SURROUND; avail++) {
+                reset_calls();
+                g_avail_from = avail; g_type = "mp3";
+                int rc = ncm_api_song_url_auto_av_f("dev", "ck", "1", vip, 0, desired, &u, &eff, fake_try);
+                int want = expect_land(vip, desired, avail);
+                int ok = (want >= 0 && rc == NCM_OK && eff == want && u.url[0] &&
+                          total_calls() == expect_tried(vip, desired, want));
+                av_cases++;
+                if (!ok) {
+                    av_bad++;
+                    printf("  FAIL  vip=%d desired=%d(%s) avail=%d -> rc=%d eff=%d calls=%d (want %d/%d)\n",
+                           vip, desired, ncm_api_level_str(desired), avail, rc, eff, total_calls(),
+                           want, expect_tried(vip, desired, want));
+                    g_fail = 1;
+                }
+            }
+        }
+    }
+    CHECK(av_bad == 0, "auto_av matrix %d cases all pass (vip 3 x desired 9 x avail 9)", av_cases);
+
+    printf("== 9) 真机场景复现：CVIP + 设置Hi-Res + 歌曲「有SQ无Hi-Res」→ 落无损SQ ==\n");
+    reset_calls();
+    g_avail_from = NCM_LEVEL_LOSSLESS;   /* 歌曲只提供到 SQ（及更低）→ 无 Hi-Res */
+    g_type = "flac";                     /* SQ 以 flac 下发 */
+    int rc9 = ncm_api_song_url_auto_av_f("d", "c", "10", NCM_VIP_CVIP, 0, NCM_LEVEL_HIRES,
+                                         &u, &eff, fake_try);
+    CHECK(rc9 == NCM_OK && eff == NCM_LEVEL_LOSSLESS && strcmp(u.type, "flac") == 0,
+          "CVIP Hi-Res、有SQ无HiRes -> 落无损SQ (rc=%d eff=%d(%s) type=%s)",
+          rc9, eff, ncm_api_level_str(eff), u.type);
+    /* 对照：若账户VIP态未就绪(NONE)，钳顶把Hi-Res压到极高，SQ被跳过（旧app clamp即此路径） */
+    reset_calls();
+    g_avail_from = NCM_LEVEL_LOSSLESS; g_type = "flac";
+    int rcn = ncm_api_song_url_auto_av_f("d", "c", "10", NCM_VIP_NONE, 0, NCM_LEVEL_HIRES,
+                                         &u, &eff, fake_try);
+    CHECK(rcn == NCM_OK && eff == NCM_LEVEL_EXHIGH,
+          "NONE+Hi-Res -> 钳到极高EXHIGH (rc=%d eff=%d) — 旧app clamp正是此路径致SQ被跳过",
+          rcn, eff);
+
     printf(g_fail ? "== DEGRADE SIM: FAIL ==\n" : "== DEGRADE SIM: ALL PASS ==\n");
     return g_fail;
 }

patch_v2/ncm_app/core/ncm_api.c

@@ -299,46 +299,95 @@ static int level_from_str(const char *s) {
     return -1;   /* sky/dolby/未知：不采信 */
 }
 
+/* 账户权限允许的最高档（§20.3，与 app/logic/account.c account_level_cap 同口径）：
+ * NONE→EXHIGH / CVIP→HIRES / SVIP→SURROUND。core 侧权威实现，供降级链自钳顶。 */
+static int level_cap_for_vip(int vip)
+{
+    switch (vip) {
+        case NCM_VIP_SVIP: return NCM_LEVEL_SURROUND;
+        case NCM_VIP_CVIP: return NCM_LEVEL_HIRES;
+        default:           return NCM_LEVEL_EXHIGH;
+    }
+}
+
+/* 逐级一次尝试：请求 lv 档，url 非空且可解码（§19：type 权威 mp3/flac；type 缺失按
+ * url 扩展名，默认当 mp3 收）→ 回填 out/out_level 返回 1；否则返回 0（该档不可用，
+ * 继续降级）。out_level 采信服务端静默降档（data[0].level < 请求档且无歧义串）；
+ * sky 族（SKY/SURROUND 同 "sky"）无法区分时保守取请求档。 */
+static int level_attempt(const char *device_id, const char *cookie, const char *id,
+                         int lv, ncm_song_url_try_fn try_fn,
+                         ncm_play_url_t *out, int *out_level)
+{
+    ncm_play_url_t p;
+    int rc = try_fn(device_id, cookie, id, lv, &p);
+    if (rc != NCM_OK) return 0;
+    int ok = ncm_streq(p.type, "mp3") || ncm_streq(p.type, "flac");
+    if (!p.type[0]) {
+        ok = 1;
+        const char *dot = strrchr(p.url, '.');
+        if (dot && ncm_streq(dot, ".flac")) ncm_strlcpy(p.type, "flac", sizeof p.type);
+    }
+    if (!(p.url[0] && ok)) return 0;   /* url 为 null 或未知格式：继续降级 */
+    *out = p;
+    if (out_level) {
+        int rl = level_from_str(p.level);
+        *out_level = (rl >= 0 && rl < lv) ? rl : lv;
+    }
+    return 1;
+}
+
 /* 降级链（§20 全档表）：从 desired 逐档向下；DOLBY(=16) 不在链内（不进 UI/不降级经过）。
- * 单次请求失败（网络/鉴权）与「该档不可用」（url null/未知格式）都继续降级。 */
+ * 单次请求失败（网络/鉴权）与「该档不可用」（url null/未知格式）都继续降级。
+ * 本函数无账户感知——信任调用方已按会员权限钳顶（app/play/player_manager.c 负责）。 */
 int ncm_api_song_url_auto_f(const char *device_id, const char *cookie, const char *id,
                             int desired, ncm_play_url_t *out, int *out_level,
                             ncm_song_url_try_fn try_fn) {
     if (!try_fn) try_fn = ncm_api_song_url;
     if (out_level) *out_level = -1;
+    /* 从 desired 往下降级：surround(sky+c51)->sky->jymaster->jyeffect->hires->lossless
+     * ->exhigh->higher->standard；DOLBY/越界钳到合法区间。 */
     int start = desired;
     if (start < NCM_LEVEL_STANDARD) start = NCM_LEVEL_STANDARD;
     if (start > NCM_LEVEL_UI_MAX)   start = NCM_LEVEL_UI_MAX;
-    /* 从 desired 往下降级：surround(sky+c51)->sky->jymaster->jyeffect->hires->lossless
-     * ->exhigh->higher->standard */
     for (int lv = start; lv >= NCM_LEVEL_STANDARD; lv--) {
-        ncm_play_url_t p;
+        if (level_attempt(device_id, cookie, id, lv, try_fn, out, out_level)) return NCM_OK;
-        int rc = try_fn(device_id, cookie, id, lv, &p);
-        if (rc != NCM_OK) continue;
-        /* §19：接受 mp3 与 flac（dr_flac 落地后无损/Hi-Res 真实生效）。
-         * type 权威；type 缺失（旧端点兼容）时看 url 扩展名，默认当 mp3 收。 */
-        int ok = ncm_streq(p.type, "mp3") || ncm_streq(p.type, "flac");
-        if (!p.type[0]) {
-            ok = 1;
-            const char *dot = strrchr(p.url, '.');
-            if (dot && ncm_streq(dot, ".flac")) ncm_strlcpy(p.type, "flac", sizeof p.type);
-        }
-        if (p.url[0] && ok) {
-            *out = p;
-            if (out_level) {
-                /* 服务端可能在 url 非空时仍静默降档（响应 data[0].level < 请求档）——
-                 * 无歧义串（standard..jymaster）且低于请求档时采信响应档；
-                 * sky 族无法区分 SKY/SURROUND，保守取请求档。 */
-                int rl = level_from_str(p.level);
-                *out_level = (rl >= 0 && rl < lv) ? rl : lv;
-            }
-            return NCM_OK;
-        }
-        /* url 为 null 或未知格式：继续降级 */
     }
     return NCM_ERR_NOTFOUND;
 }
 
+int ncm_api_song_url_auto_av_f(const char *device_id, const char *cookie, const char *id,
+                               int account_vip, int fee, int desired,
+                               ncm_play_url_t *out, int *out_level,
+                               ncm_song_url_try_fn try_fn) {
+    if (!try_fn) try_fn = ncm_api_song_url;
+    if (out_level) *out_level = -1;
+    /* fee 门禁（§20.4，BIZ_NOTES §3 社区口径）：VIP 才能听（1=VIP 曲 / 4=付费专）且
+     * 账户不足 CVIP → 不发任何 url 请求，直接 NCM_ERR_VIP（省请求，防风控）；
+     * fee=0/8 放行（8=免费听低音质，播放允许）。 */
+    if ((fee == 1 || fee == 4) && account_vip < NCM_VIP_CVIP)
+        return NCM_ERR_VIP;
+    /* 账户权限钳顶：desired 超出账户可达档 → 压到上限（免去注定空 url 的高档请求）。
+     * 与 player_manager 的钳顶同口径，此处按真实 account_vip 自钳，避免调用方漏钳/
+     * 错钳导致 SQ 被跳过。 */
+    int cap = level_cap_for_vip(account_vip);
+    if (desired > cap) desired = cap;
+    if (desired < NCM_LEVEL_STANDARD) desired = NCM_LEVEL_STANDARD;
+    /* 逐级降级：只试账户可访问的档（ncm_api_level_gate(lv)<=account_vip），越权档跳过
+     * （注定空 url，风控不试）；落在「账户可访问且歌曲提供」的最近可用档。 */
+    for (int lv = desired; lv >= NCM_LEVEL_STANDARD; lv--) {
+        if (ncm_api_level_gate(lv) > account_vip) continue;
+        if (level_attempt(device_id, cookie, id, lv, try_fn, out, out_level)) return NCM_OK;
+    }
+    return NCM_ERR_NOTFOUND;
+}
+
+int ncm_api_song_url_auto_av(const char *device_id, const char *cookie, const char *id,
+                             int account_vip, int fee, int desired,
+                             ncm_play_url_t *out, int *out_level) {
+    return ncm_api_song_url_auto_av_f(device_id, cookie, id, account_vip, fee, desired,
+                                      out, out_level, NULL);
+}
+
 int ncm_api_song_url_auto(const char *device_id, const char *cookie, const char *id,
                           int desired, ncm_play_url_t *out, int *out_level) {
     return ncm_api_song_url_auto_f(device_id, cookie, id, desired, out, out_level, NULL);

patch_v2/ncm_app/core/ncm_api.h

@@ -113,6 +113,21 @@ int ncm_api_song_url_auto_f(const char *device_id, const char *cookie, const cha
                             int desired, ncm_play_url_t *out, int *out_level,
                             ncm_song_url_try_fn try_fn);
 
+/* 账户/fee 感知的降级链（§20.3 权威形态，修「SQ 被跳过」类降级链 bug）：
+ * 内部先做 fee 门禁（fee∈{1,4} 且 account_vip<CVIP → NCM_ERR_VIP，零请求）→ 按
+ * account_vip 自钳顶（NONE→EXHIGH/CVIP→HIRES/SVIP→SURROUND）→ 只试账户可访问的档
+ *（ncm_api_level_gate(lv)<=account_vip）→ 落在「账户可访问且歌曲提供」的最近可用档。
+ * 比 ncm_api_song_url_auto 更稳：即便调用方漏钳/错钳（如账户 VIP 态未就绪时被压到
+ * EXHIGH），只要传入真实 account_vip，无损 SQ 不会被跳过。调用方应改请本函数（app 层
+ * account_vip()+song.fee）。_f 变体可注入 try_fn 供离线 sim。 */
+int ncm_api_song_url_auto_av(const char *device_id, const char *cookie, const char *id,
+                             int account_vip, int fee, int desired,
+                             ncm_play_url_t *out, int *out_level);
+int ncm_api_song_url_auto_av_f(const char *device_id, const char *cookie, const char *id,
+                               int account_vip, int fee, int desired,
+                               ncm_play_url_t *out, int *out_level,
+                               ncm_song_url_try_fn try_fn);
+
 /* 会员信息（BIZ_NOTES §1）：vip/info v2 优先、v1 兜底（均 weapi）。
  * 风控：只在「登录后 / 缓存超 1 天 / 到期后」由 App 层触发一次，不轮询。 */
 typedef struct ncm_vip_info {