Completes the escrow feature on top of the tested core (src/lib/cashuEscrow.ts):
- useCashuEscrow: native-only hook wiring createEscrow (cashu-ts mint + NWC/WebLN
funding), redeemEscrow, escrow-key derivation (coco keyring) and profile publish
- EscrowKeyCard (Wallet): advertise the kind-0 'cashu_escrow' pubkey
- EscrowRequestDialog (listing card): buyer locks funds (P2PK to seller, refundable
after N days) and sends the 31872 carrying the cashu_token
- EscrowPanel + 'Redeem escrow' in the DM request banner (seller side); the panel
is offline/parse-based so it renders on web too
- Buyer 'Escrow & request' supersedes the plain request when available
EXPERIMENTAL: mint-touching paths are unverified on a device (native-only wallet);
use small amounts first. Gate: 101 tests, 0 errors.
