feat(auth): clarify login identity and speed up mobile entry

tools/prepare_h5_assets.py

@@ -12,6 +12,8 @@ for name in ['bg-splash', 'bg-login', 'bg-profile', 'bg-history', 'bg-report']:
     # Native status/navigation area belongs to the host, not the H5 document.
     top = 253 if name == 'bg-report' else 248
     source.crop((0, top, source.width, source.height)).save(root / (name + '-h5.jpg'), quality=92, optimize=True)
+    # Mobile delivery variant; preserve the full-resolution PSD exports/JPEGs.
+    Image.open(root / (name + '-h5.jpg')).save(root / (name + '-h5.webp'), quality=85, method=6)
 
 geometry = []
 for direction in ['front', 'left', 'right']: