add fake ecdh share and dleq proof to P2SH input for valid test: two inputs using per-input ECDH shares - only eligible inputs contribute shares (P2SH excluded)
remove unused return string from is_input_eligible
Add support for computing bip352 output scripts
Extract ECDH shares and public key from PSBT and aggregate both if necessary
Refactor validate_ecdh_coverage to use collect_input_ecdh_and_pubkey
