修: run_pinned 把 capture_output 传给 Popen 导致 TypeError

subprocess.run 的 capture_output 是它的语法糖，Popen 不认这个参数 → run()/_sh 这三个
ffmpeg 调用点全炸，三个 lane 在 2.5 分钟内秒失败 64 项（每项 attempts 用光变 failed）。
补上展开: capture_output=True → stdout/stderr=PIPE。本地与生产均已复验 rc=0。

scripts/library_run.py

@@ -82,6 +82,13 @@ def pin_child(pid):
 def run_pinned(cmd, timeout=None, **kw):
     """subprocess.run() with the child pinned to CHILD_MASK (see pin_child)."""
     kw.setdefault("creationflags", NOWIN)
+    # `capture_output` is a subprocess.run() convenience Popen does not accept - expand it here,
+    # otherwise every caller that passes it dies with
+    # "Popen.__init__() got an unexpected keyword argument 'capture_output'" (measured: all three
+    # lanes failed every item within a second of this wrapper being introduced).
+    if kw.pop("capture_output", False):
+        kw.setdefault("stdout", subprocess.PIPE)
+        kw.setdefault("stderr", subprocess.PIPE)
     p = subprocess.Popen(cmd, **kw)
     pin_child(p.pid)
     try: