Performs liveness verification using a selfie image. Delegates to the configured verification provider with verification_type="liveness".

Supported media types: jpeg/jpg, png, BMP.

Guidelines:

• Higher image size increases upload and processing time; reduce image size while preserving required quality.
• Minimum recommended image size: 300x300 pixels with the face covering ~75% of the frame (≈220x220).
• Capture only live photographs — do not use printed photos or video-graphed frames.
• Background should be plain white and no other person should appear in the frame.
• Capture vertically (portrait), avoid skew/tilt; watermark (if any) must be readable.
• Ensure good lighting so the user is clearly visible and recognizable.