feat(music-render): providers/local.py — MusicGen client (SP-5)

NAS music-lab/app/local_provider.py 이식. DB 호출 webhook 변환.
MusicGen 호스트는 host.docker.internal:8765 (Windows native).
결과 MP3는 /mnt/nas/webpage/data/music/에 직접 저장.
Plan-B-Music Phase 2.

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

services/music-render/providers/local.py

@@ -0,0 +1,105 @@
+"""Local MusicGen Provider — Windows AI 머신의 native MusicGen 서버(:8765) 호출.
+
+NAS music-lab/app/local_provider.py 이식. DB 호출만 webhook으로 변환.
+"""
+from __future__ import annotations
+
+import logging
+import os
+import time
+
+import requests
+
+from nas_client import webhook_update_task, webhook_add_track
+
+logger = logging.getLogger(__name__)
+
+MUSIC_AI_SERVER_URL = os.getenv("MUSIC_AI_SERVER_URL", "")
+MUSIC_MEDIA_ROOT = os.getenv("MUSIC_MEDIA_ROOT", "/mnt/nas/webpage/data/music")
+MUSIC_MEDIA_BASE = os.getenv("MUSIC_MEDIA_URL_PREFIX", "/media/music")
+
+
+def run_local_generation(task_id: str, params: dict) -> None:
+    """MusicGen 생성 → /mnt/nas/.../music/{task_id}.mp3 저장 → add_track."""
+    try:
+        webhook_update_task(task_id, "processing", 10, "AI 서버에 연결 중...")
+        if not MUSIC_AI_SERVER_URL:
+            webhook_update_task(task_id, "failed", 0, "", error="MUSIC_AI_SERVER_URL 미설정")
+            return
+
+        webhook_update_task(task_id, "processing", 30, "음악 생성 중...")
+        resp = requests.post(f"{MUSIC_AI_SERVER_URL}/generate", json=params, timeout=30)
+        if resp.status_code != 200:
+            webhook_update_task(task_id, "failed", 0, "",
+                                error=f"AI 서버 오류: {resp.status_code} {resp.text[:200]}")
+            return
+
+        ai_task_id = resp.json().get("task_id")
+        if not ai_task_id:
+            webhook_update_task(task_id, "failed", 0, "", error="AI 서버 응답에 task_id 없음")
+            return
+
+        remote_url = None
+        for _ in range(120):
+            time.sleep(5)
+            sr = requests.get(f"{MUSIC_AI_SERVER_URL}/status/{ai_task_id}", timeout=10)
+            sd = sr.json()
+            st = sd.get("status")
+            prog = sd.get("progress", 0)
+            msg = sd.get("message", "음악 생성 중...")
+            scaled = 30 + int(prog * 0.49)
+            webhook_update_task(task_id, "processing", scaled, msg)
+
+            if st == "succeeded":
+                remote_url = sd.get("audio_url")
+                break
+            elif st == "failed":
+                webhook_update_task(task_id, "failed", 0, "",
+                                    error=sd.get("error", "AI 서버 생성 실패"))
+                return
+
+        if not remote_url:
+            webhook_update_task(task_id, "failed", 0, "", error="AI 서버 타임아웃 (10분)")
+            return
+
+        webhook_update_task(task_id, "processing", 80, "파일 저장 중...")
+        filename = f"{task_id}.mp3"
+        os.makedirs(MUSIC_MEDIA_ROOT, exist_ok=True)
+        file_path = os.path.join(MUSIC_MEDIA_ROOT, filename)
+
+        dl = requests.get(remote_url, timeout=120, stream=True)
+        with open(file_path, "wb") as f:
+            for chunk in dl.iter_content(chunk_size=8192):
+                f.write(chunk)
+
+        audio_url = f"{MUSIC_MEDIA_BASE}/{filename}"
+        genre = params.get("genre", "")
+        moods = params.get("moods", [])
+        mood_str = moods[0] if moods else "Original"
+        title = params.get("title") or (
+            f"{genre} — {mood_str} Mix" if genre else f"{mood_str} Mix"
+        )
+
+        track = {
+            "title": title,
+            "genre": genre,
+            "moods": moods,
+            "instruments": params.get("instruments", []),
+            "duration_sec": params.get("duration_sec"),
+            "bpm": params.get("bpm"),
+            "key": params.get("key", ""),
+            "scale": params.get("scale", ""),
+            "prompt": params.get("prompt", ""),
+            "audio_url": audio_url,
+            "file_path": f"/app/data/{filename}",
+            "task_id": task_id,
+            "provider": "local",
+        }
+        webhook_add_track(task_id, "succeeded", 100, "생성 완료",
+                          audio_url=audio_url, track=track)
+
+    except requests.Timeout:
+        webhook_update_task(task_id, "failed", 0, "", error="AI 서버 타임아웃")
+    except Exception as e:
+        logger.exception("local generation error task=%s", task_id)
+        webhook_update_task(task_id, "failed", 0, "", error=str(e))