Zcash shielded transaction integration

[alexs-scalar]

Trezor currently supports Zcash only for transparent t-address transactions, but shielded transactions are the core feature of Zcash.

There was already meaningful work done in PR #2472 for Orchard shielded transaction support:

#2472

Could the Trezor team please put Zcash shielded transaction support back on the priority list?

If there’s some blockers, suite integration requirements, or other work needed, please let the community know so we can help move this forward.

Thank you.