fix(keys): 插孔消抖 + 音量 ramp 3s 上限 + 亮度写日志 — 耳机插拔 ADC 幽灵音量键修复

真机实证(meow_20260901_034946.log): 4.4 插入瞬间电气瞬态在 jz_adc_aux(event2)
产生 VOL_UP 幽灵按住, vol_ramp 24%→上限50 (225391 ramp 起→227213 爬满,
紧随 audiod jack changed). 修(限 meow_launcherd/+meow_watchdog/):
① launcher audio.c + watchdog 各自读 /sys/class/switch/{headset,balance}/state
  (节流缓存 1s/500ms, 热路径不每圈读文件), 变化后 800ms 内忽略音量键边沿
  (vol_ramp_begin 不起/在爬 ramp 中止/wd_vol_adj 单步忽略)
② ramp 总时长上限 VOL_RAMP_MAX_MS=3000 兜底防一次幽灵打满(正常长按 24→50 ~1.4s 不伤)
③ write_brightness(val,src) 全 10 调用点带源+逐写 logmsg, 亮度跳上限下次可定位
  (grep 全库: 写 backlight 仅 launcher/watchdog/svc_power/bootmenu, 无确定 255 路径)
宿主: 新 test_vol_ramp_jack 15/15 PASS(单击/长按回归+3s cap+消抖忽略/中止/恢复);
test_wd_fw 17/17 + test_settings_brightness + test_notif_tf PASS; MIPS -Wall -Wextra 0 warning
(顺带修 watchdog 既有 sys/poll.h→poll.h 重定向 warning).
watchdog 已热更设备 /usr/data(baa997ea); launcher 7be1d4eb 待固件. fw_content.conf 已更新.
遗留: SDK meow_ui_input.c 音量键路径需同款消抖(sdk/ 有主未动)

patch_v2/meow_launcherd/backlight.c

@@ -41,7 +41,7 @@ void apply_user_brightness(void)
     }
     int v = meow_settings_brightness_clamped();
     if (v <= 0) v = 60;   /* 防御：clamp 后不可能 ≤0，仅兜底 */
-    write_brightness(v);
+    write_brightness(v, "apply_user_brightness");
     g_sys.brightness = v;
     meow_brightness_pending = 0;
     logmsg("apply user brightness (MeowOS takeover) -> %d", v);
@@ -73,13 +73,16 @@ static void write_file(const char *path, const char *val)
 }
 
 
-void write_brightness(int val)
+void write_brightness(int val, const char *src)
 {
+    /* 亮度幽灵排查（2026-09-01：用户报告插耳机瞬间亮度自己跳到 raw 上限，写者未知）：
+     * 每次写背光都留值+调用源线索，下次「亮度自己跳」可直接定位写者。 */
     char buf[8];
     int l = snprintf(buf, sizeof buf, "%d\n", val);
     int fd = open(BACKLIGHT, O_WRONLY);
-    if (fd < 0) { logmsg("backlight open fail: %s", strerror(errno)); return; }
-    if (write(fd, buf, l) < 0) logmsg("backlight write %d: %s", val, strerror(errno));
+    if (fd < 0) { logmsg("backlight <- %d (src=%s) open fail: %s", val, src, strerror(errno)); return; }
+    if (write(fd, buf, l) < 0) logmsg("backlight <- %d (src=%s): %s", val, src, strerror(errno));
+    else logmsg("backlight <- %d (src=%s)", val, src);
     close(fd);
 }
 
@@ -107,7 +110,7 @@ void ensure_backlight(void)
     }
     int target = (saved_brightness > 0) ? saved_brightness : 60;
     logmsg("backlight off (cur=%d bl_power=%d) -> %d", cur, blp, target);
-    if (cur <= 0) write_brightness(target);
+    if (cur <= 0) write_brightness(target, "ensure_backlight");
     if (blp > 0) write_file(BACKLIGHT_POWER, "0\n");
 }
 
@@ -126,7 +129,7 @@ void restore_backlight(void)
 {
     if (menu_opened_blank) {
         logmsg("restore: panel was blanked at menu open, re-blank (0 + FBIOBLANK 4)");
-        write_brightness(0);
+        write_brightness(0, "restore_backlight(re-blank)");
         int fbfd = open(FB_DEV, O_RDWR);
         if (fbfd >= 0) { ioctl(fbfd, FBIOBLANK, 4); close(fbfd); }
         menu_opened_blank = 0;
@@ -138,7 +141,7 @@ void restore_backlight(void)
         int target = (saved_brightness > 0) ? saved_brightness : 60;
         logmsg("restore backlight (cur=%d bl_power=%d) -> %d (saved=%d)",
                cur, blp, target, saved_brightness);
-        if (cur <= 0) write_brightness(target);
+        if (cur <= 0) write_brightness(target, "restore_backlight");
         if (blp > 0) write_file(BACKLIGHT_POWER, "0\n");
     }
 }