Hardware wallet: passphrase (hidden) wallet pairing

[piotr-iohk]

Part of #589.

Spec (canonical): synonymdev/bitkit-android#1060 — scope, Figma, acceptance criteria, and open questions live there. Comment on that issue for cross-platform decisions.

Related: #613 / synonymdev/bitkit-android#1030 — reconnect/signing safety for passphrase identities.

iOS deliverables

• Connect Hardware Paired step: Passphrase action → Enter Passphrase → Passphrase Paired (per Figma in android#1060).
• Host and/or on-device passphrase entry on capable Trezors (Safe 5/7).
• Separate watch-only identity per passphrase (walletKey / home tile / HW settings row).
• Add passphrase wallet from Hardware Wallets settings after initial pairing.
• Zero-balance add with non-blocking warning; reject duplicate xpub.
• Never persist passphrase; signing/reconnect scoped to paired identity.
• Parity with Android implementation of android#1060.

[mattcashman407-eng]

@piotr-iohk Have you been able to resolve this issue ?