FIX: Đã fix cross-machine (v202608060700)

app/api/v1/plugins.py

@@ -151,7 +151,11 @@ async def delete_soundfont(sf_id: str, current_user: dict = Depends(get_current_
 @router.get("/soundfonts/download/{sf_id}")
 async def download_soundfont_asset(sf_id: str):
     clean_id = sf_id.replace("sf_", "") if sf_id.startswith("sf_") else sf_id
-    for base_dir in [UPLOAD_SF_DIR, SYSTEM_SF_DIR]:
+    # Cũng tìm trong static/soundfonts (font bundled theo deployment) — trước
+    # đây chỉ UPLOAD + SYSTEM → font bundled 404 → incognito (IndexedDB rỗng)
+    # không tải được font → instrument CÂM (browser thường dùng cache nên OK).
+    static_sf_dir = os.path.join(os.path.dirname(os.path.dirname(os.path.dirname(__file__))), "static", "soundfonts")
+    for base_dir in [UPLOAD_SF_DIR, SYSTEM_SF_DIR, static_sf_dir]:
         if not os.path.isdir(base_dir):
             continue
         # Prefer SF2: the client FluidSynth WASM cannot decode SF3 (Ogg Vorbis)