Function bech32_encode 

pub fn bech32_encode(
    hrp: &str,
    witness_version: u8,
    program: &[u8],
) -> Result<String, SignerError>

Encode a SegWit/Taproot address using Bech32 (v0) or Bech32m (v1+).

Automatically selects the correct variant based on witness version.