feat(music-render): nas_client webhook adapter (SP-5)

NAS DB 직접 접근 불가 → webhook_update_task/webhook_add_track으로 변환.
X-Internal-Key 헤더 자동 첨부. 실패 시 raise 안 함 (logger.error).
env var는 call time에 읽어 monkeypatch 테스트 호환성 확보.
Plan-B-Music Phase 2.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

services/music-render/nas_client.py

@@ -0,0 +1,80 @@
+"""NAS webhook 어댑터 — Windows worker가 NAS DB 직접 접근 못하므로 HTTP로 위임.
+
+기존 NAS suno_provider/local_provider의 `update_task`, `add_track` 호출을
+이 모듈의 webhook_update_task/webhook_add_track으로 치환.
+
+webhook 실패는 raise하지 않고 logger.error로 기록 (provider 로직 흐름 유지).
+"""
+from __future__ import annotations
+
+import logging
+import os
+from typing import Any, Dict, Optional
+
+import httpx
+
+logger = logging.getLogger(__name__)
+
+_TIMEOUT = 10.0
+
+
+def _post(payload: Dict[str, Any]) -> None:
+    nas_base_url = os.getenv("NAS_BASE_URL", "http://192.168.45.54:18600")
+    internal_api_key = os.getenv("INTERNAL_API_KEY", "")
+    url = f"{nas_base_url}/api/internal/music/update"
+    try:
+        r = httpx.post(
+            url,
+            headers={"X-Internal-Key": internal_api_key},
+            json=payload,
+            timeout=_TIMEOUT,
+        )
+        if r.status_code != 200:
+            logger.error("webhook %s returned %d: %s",
+                         payload.get("task_id"), r.status_code, r.text[:200])
+    except Exception:
+        logger.exception("webhook %s 호출 실패", payload.get("task_id"))
+
+
+def webhook_update_task(
+    task_id: str,
+    status: str,
+    progress: int,
+    message: str = "",
+    audio_url: Optional[str] = None,
+    error: Optional[str] = None,
+) -> None:
+    """기존 update_task(task_id, status, progress, message, audio_url=None, error=None) 대체."""
+    payload: Dict[str, Any] = {
+        "task_id": task_id,
+        "status": status,
+        "progress": progress,
+        "message": message,
+    }
+    if audio_url is not None:
+        payload["audio_url"] = audio_url
+    if error is not None:
+        payload["error"] = error
+    _post(payload)
+
+
+def webhook_add_track(
+    task_id: str,
+    status: str,
+    progress: int,
+    message: str = "",
+    audio_url: Optional[str] = None,
+    track: Optional[Dict[str, Any]] = None,
+) -> None:
+    """update + add_track을 한 webhook 호출로 결합 (NAS internal_router가 둘 다 처리)."""
+    payload: Dict[str, Any] = {
+        "task_id": task_id,
+        "status": status,
+        "progress": progress,
+        "message": message,
+    }
+    if audio_url is not None:
+        payload["audio_url"] = audio_url
+    if track is not None:
+        payload["track"] = track
+    _post(payload)