fix(windows): fix numpy DLL loading in embedded Python distribution

- Generate numpy/_distributor_init_local.py during build so libopenblas
  can be located when running from the Windows installer
- Add os.add_dll_directory() call at runtime as a fallback for embedded Python

media_server/services/audio_analyzer.py

@@ -15,6 +15,21 @@ def _load_numpy():
     global _np
     if _np is None:
         try:
+            import os
+            import sys
+            if sys.platform == 'win32':
+                # Embedded Python doesn't auto-load DLLs from numpy.libs;
+                # add the directory explicitly so libopenblas can be found.
+                try:
+                    import importlib.util
+                    spec = importlib.util.find_spec('numpy')
+                    if spec and spec.submodule_search_locations:
+                        numpy_dir = list(spec.submodule_search_locations)[0]
+                        libs_dir = os.path.join(os.path.dirname(numpy_dir), 'numpy.libs')
+                        if os.path.isdir(libs_dir):
+                            os.add_dll_directory(libs_dir)
+                except Exception:
+                    pass
             import numpy as np
             _np = np
         except Exception as e: