Improve JUC500 device discovery and Windows doctor diagnostics

Widen libusb DLL search, copy DLL into venv on setup, match sibling
PIDs, and add doctor command with PnP VID_0711 hints for WinUSB.

Co-authored-by: Cursor <cursoragent@cursor.com>

juc500_xfer/cli.py

@@ -10,7 +10,7 @@ from pathlib import Path
 
 from . import __version__
 from .protocol import Session
-from .usb_link import list_devices, Juc500Link
+from .usb_link import list_devices, Juc500Link, doctor
 
 
 def _progress(prefix: str):
@@ -34,13 +34,39 @@ def _progress(prefix: str):
 def cmd_info(_args: argparse.Namespace) -> int:
     devices = list_devices()
     if not devices:
-        print("연결된 JUC500 장치가 없습니다.")
+        print("연결된 JUC500 장치가 없습니다. 진단: python -m juc500_xfer doctor")
         return 1
     for d in devices:
-        print(f"bus={d.bus} addr={d.address} serial={d.serial!r} product={d.product!r}")
+        print(
+            f"{d.vid:04x}:{d.pid:04x} bus={d.bus} addr={d.address} "
+            f"serial={d.serial!r} product={d.product!r}"
+        )
     return 0
 
 
+def cmd_doctor(_args: argparse.Namespace) -> int:
+    rep = doctor()
+    print(f"libusb: {rep.libusb_path or '(없음)'}")
+    if rep.libusb_error:
+        print(f"libusb 오류: {rep.libusb_error}")
+    print(f"USB 장치 수(libusb): {rep.usb_device_count}")
+    print(f"JUC500 후보: {len(rep.juc500)}")
+    for j in rep.juc500:
+        print(f"  - {j}")
+    if rep.sample_devices:
+        print("USB 샘플:")
+        for line in rep.sample_devices:
+            print(f"  {line}")
+    if rep.pnp_vid0711:
+        print("Windows PnP VID_0711:")
+        for row in rep.pnp_vid0711:
+            print(f"  - {row}")
+    print("안내:")
+    for h in rep.hints:
+        print(f"  * {h}")
+    return 0 if rep.ok else 1
+
+
 def cmd_probe(args: argparse.Namespace) -> int:
     with Juc500Link(serial=args.serial) as link:
         print(f"열림: serial={link.serial!r}")
@@ -114,6 +140,9 @@ def build_parser() -> argparse.ArgumentParser:
     s = sub.add_parser("info", help="연결된 JUC500 장치 목록")
     s.set_defaults(func=cmd_info)
 
+    s = sub.add_parser("doctor", help="USB/libusb/WinUSB 진단")
+    s.set_defaults(func=cmd_doctor)
+
     s = sub.add_parser("probe", help="USB 인터페이스 점유 및 송수신 프로브")
     s.add_argument("--serial", default=None)
     s.set_defaults(func=cmd_probe)